Calorifiers and heat source management?

[T_i_m]

Hi all,

 

One of an ever decreasing list of things I haven't even seen on my elderly friends 70' LANB is the cauliflower but now we have the Webasto TTC up and running, it raised some questions.

 

I think the engine cooling runs through the cauliflower. I say 'think' because as I say, I've not seen it or the feeding pipework so can only go by what I'm told and I believe he has said it does. However, he has also said he tried having a shower the other day but the water was too cold so that means:

 

a) He's run out what little engine heated water was there.

 

b) Whilst it was engine heated warm to full temp, it was still too cold to take as a 'hot shower'.

 

c) The engine isn't heating the water because of some issue (blockage / air lock).

 

d) The engine doesn't actually heat the water.

 

Now if the answer is actually d then I'm happy with how the rest works, (assuming a LANB cauliflower is / works like a domestic CH indirect hot water cylinder) and if it's c, is there a a common cause?

 

Answers  b or a are 'it is what it is' and so also 'ok'.

 

So the question is around the assumption that both the engine and TTC do run though the cauliflower and that means this mind would like to learn if there is any form of 'automagic' thermal source management, be it some sort of thermo-set valve(s) (doubtful) or the location of the coils in the cauliflower body, with the engine one in the bottom and the TTC above (or some such)?

 

My thoughts are  .... say the engine does heat the water and to say only ~40 DegC and the TTC takes it to ~70 DegC and assuming an ambient 20 DegC starting point.

 

If the engine isn't running then the TTC will happily take it to 70 DegC.

If the TTC isn't running the engine will take it to 40 DegC

 

If they are both running then the TTC will be trying to take it to 70 but the engine (effectively) cooling it to 40? And / or the TTC trying to also heat the engine cooling cct to 70 DegC etc?

 

?

Edited May 3 by T_i_m

[Rob-M]

The usual arrangement is twin coils in the cauliflower, one for the heating circuit and one for the engine circuit.  It may be the engine wasn't run long enough to get the water up to temperature.  We usually find about 1 to 2 hours of engine running gets the water to hot shower temperature.  In summer if we don't move then an hour a day of webasto keeps the hot water hot, if moving then we will be doing a days cruising so plenty of hot water.

[T_i_m]

1 minute ago, Rob-M said:

The usual arrangement is twin coils in the cauliflower, one for the heating circuit and one for the engine circuit.  It may be the engine wasn't run long enough to get the water up to temperature.  We usually find about 1 to 2 hours of engine running gets the water to hot shower temperature.  In summer if we don't move then an hour a day of webasto keeps the hot water hot, if moving then we will be doing a days cruising so plenty of hot water.

Ok, so the design is pretty simple / logical and it's not uncommon for both the TTC and engine to run through the cauliflower (check).

 

In this case I think he has said that running the engine (typically at least one hour, morning and evening) doesn't heat the water very much. Is that likely to vary based on the engine, this is a Beta 50?

 

If it should, could we be looking at an issue on that cct? I might try to find my infra-red thermometer and have it with me when visiting the NB next and see what I find. Like, if I can get to the engine cooling pipes, especially the return then I'm guessing the hot water in the cauliflower should be around that temp, given a long enough engine run?

[Tony Brooks]

You also need to check that the engine is reaching running temperature within (say) 15 minutes. If not, then the engine thermostat is probably missing or stuck open. A calorifier can only heat the water as hot as the water in the coils.

 

The calorifier coil is normally in parallel with the skin tank, so the full coolant flow does not pass through it. It is typically connected via car heater size hose/pipes.

 

He also needs to get some load on the engine, so running on tick over will extend the warm-up time. I advocate running it at the speed (in neutral) that gives the highest charge, so the alternator loads the engine to a degree. He can reduce the speed as the charging rate drops, but still maintain the highest charge.

 

I don't think an hour morning and evening is the same as two hours on the trot, because two separate hours requires the engine to get up to temperature twice, not once and hold that temperature.

 

Calorifier coils can and do airlock, so there is no, or very little engine coolant passing through the calorifier. Once the engine is up to temperature

 

There is no need for any fancy thermal valves or such like because even if both sources were running at full temperature the water in the calorifier can not get any hotter than the hottest source, so nothing can boil. What he may have is a manual valve that lets him isolate the Webasto from the radiators during the summer, but that will not normally affect the engine heating circuit.

 

 

[T_i_m]

1 minute ago, Tony Brooks said:

You also need to check that the engine is reaching running temperature within (say) 15 minutes. If not, then the engine thermostat is probably missing or stuck open. A calorifier can only heat the water as hot as the water in the coils.

 

The calorifier coil is normally in parallel with the skin tank, so the full coolant flow does not pass through it. It is typically connected via car heater size hose/pipes.

 

He also needs to get some load on the engine, so running on tick over will extend the warm-up time. I advocate running it at the speed (in neutral) that gives the highest charge, so the alternator loads the engine to a degree. He can reduce the speed as the charging rate drops, but still maintain the highest charge.

 

I don't think an hour morning and evening is the same as two hours on the trot, because two separate hours requires the engine to get up to temperature twice, not once and hold that temperature.

 

Calorifier coils can and do airlock, so there is no, or very little engine coolant passing through the calorifier. Once the engine is up to temperature

 

There is no need for any fancy thermal valves or such like because even if both sources were running at full temperature the water in the calorifier can not get any hotter than the hottest source, so nothing can boil. What he may have is a manual valve that lets him isolate the Webasto from the radiators during the summer, but that will not normally affect the engine heating circuit.

 

 

Hi Tony and thanks for the complete reply. All noted.

 

Being a Beta 50 with a Travel Power unit I have advised he run the engine at at least 1200 RPM when charging. On the move, 1200 RPM would be good for water skiing. 😉 

 

On the last point, my question wasn't assuming that say 70 DegC from the TTC + 40 DegC from the engine = boiling water, rather that the 40 from the engine would cool the 70 from the TTC, resulting in some temperature in-between?

 

Or (and less likely considering the masses / volumes / transfer efficiencies concerned), the TTC heating up the engine coolant?

[Tony Brooks]

1 minute ago, T_i_m said:

Hi Tony and thanks for the complete reply. All noted.

 

Being a Beta 50 with a Travel Power unit I have advised he run the engine at at least 1200 RPM when charging. On the move, 1200 RPM would be good for water skiing. 😉 

 

On the last point, my question wasn't assuming that say 70 DegC from the TTC + 40 DegC from the engine = boiling water, rather that the 40 from the engine would cool the 70 from the TTC, resulting in some temperature in-between?

 

Or (and less likely considering the masses / volumes / transfer efficiencies concerned), the TTC heating up the engine coolant?

 

A typical "marine" thermostat is likely to be between 65 and 70 C, but often automotive thermostats are used at around the 82 to 85 C mark, so providing the engine is brought up to temperature there is not going to be much "dilution" of the domestic water heat either way.

 

A good way of loading the engine with a Travelpower is if he did his hoovering, or used a toaster/microwave to cook his breakfast while running the engine. In fact, fitting and using an immersion heater would speed the whole process up - providing he turned the immersion heater off before stopping the engine. I suspect a relay from an ignition feed would sort that without any manual intervention.

[dmr]

6 minutes ago, Tony Brooks said:

 

A typical "marine" thermostat is likely to be between 65 and 70 C, but often automotive thermostats are used at around the 82 to 85 C mark, so providing the engine is brought up to temperature there is not going to be much "dilution" of the domestic water heat either way.

 

A good way of loading the engine with a Travelpower is if he did his hoovering, or used a toaster/microwave to cook his breakfast while running the engine. In fact, fitting and using an immersion heater would speed the whole process up - providing he turned the immersion heater off before stopping the engine. I suspect a relay from an ignition feed would sort that without any manual intervention.

 

And as you have a TravelPower it is possible that there is also an immersion heater, doubly good as you can load up the engine, possibly warm the engine faster (inially) and get the calorifier hotter quicker.

[T_i_m]

22 minutes ago, Tony Brooks said:

 

A typical "marine" thermostat is likely to be between 65 and 70 C, but often automotive thermostats are used at around the 82 to 85 C mark, so providing the engine is brought up to temperature there is not going to be much "dilution" of the domestic water heat either way.

 

A good way of loading the engine with a Travelpower is if he did his hoovering, or used a toaster/microwave to cook his breakfast while running the engine. In fact, fitting and using an immersion heater would speed the whole process up - providing he turned the immersion heater off before stopping the engine. I suspect a relay from an ignition feed would sort that without any manual intervention.

Thanks for the typical temperatures Tony.

 

Funnily, I did actually ask if he knew if he had a port for a conventional immersion heater and he said there was one but unused and blanked off etc but added 'they use a lot of power'. I reminded him of the chances the TP would be doing little during normal charging runs (the DB alternator seems to do the heavy lifting there) and so it was a shame he didn't make use of it but he said he doesn't like 'electrics' around such things. ;-(

 

I think I will need to do some further investigation but I'll not be rushing (as he seems to be reasonably well covered for now). 😉 

21 minutes ago, dmr said:

 

And as you have a TravelPower it is possible that there is also an immersion heater, doubly good as you can load up the engine, possibly warm the engine faster (initially) and get the calorifier hotter quicker.

Yeah, that all makes good sense but it seems it's tricky to get him out of his 'routine' for anything. Like, when I started the engine before leaving the other night after re-fitting the TTC, I noted the engine was set to idle at less than 1000 RPM (supposed to be 1200+ for that Engine / TP combo).

 

I still don't believe he's changed the oil ... so that could be at least at least a year and certainly not the 3 month intervals we calculated. I offered to order the oil in and deliver it to the boat and even help him doing it (I think he said it takes 'ages' to hand pump it out?) but he doesn't seem concerned.

 

But it is his boat so ....

 

Plus, I'm already a 24/7 carer for my wife, I'm not looking for (any more / unpaid) work, much as I find it interesting and like helping. (Actually, I feel sorry for the engine). ;-(

[dmr]

36 minutes ago, T_i_m said:

Thanks for the typical temperatures Tony.

 

Funnily, I did actually ask if he knew if he had a port for a conventional immersion heater and he said there was one but unused and blanked off etc but added 'they use a lot of power'. I reminded him of the chances the TP would be doing little during normal charging runs (the DB alternator seems to do the heavy lifting there) and so it was a shame he didn't make use of it but he said he doesn't like 'electrics' around such things. ;-(

 

I think I will need to do some further investigation but I'll not be rushing (as he seems to be reasonably well covered for now). 😉 

Yeah, that all makes good sense but it seems it's tricky to get him out of his 'routine' for anything. Like, when I started the engine before leaving the other night after re-fitting the TTC, I noted the engine was set to idle at less than 1000 RPM (supposed to be 1200+ for that Engine / TP combo).

 

I still don't believe he's changed the oil ... so that could be at least at least a year and certainly not the 3 month intervals we calculated. I offered to order the oil in and deliver it to the boat and even help him doing it (I think he said it takes 'ages' to hand pump it out?) but he doesn't seem concerned.

 

But it is his boat so ....

 

Plus, I'm already a 24/7 carer for my wife, I'm not looking for (any more / unpaid) work, much as I find it interesting and like helping. (Actually, I feel sorry for the engine). ;-(

 

I did read (on the www 😀) of a farmer in America who never changed the oil on his new tractor and claimed that the money saved on services more than compensated for the slightly shorter life of the engine.  A high risk approach but interesting. 

[T_i_m]

Just now, dmr said:

 

I did read (on the www 😀) of a farmer in America who never changed the oil on his new tractor and claimed that the money saved on services more than compensated for the slightly shorter life of the engine.  A high risk approach but interesting. 

A mate never changed the oil in his Ford Mondeo in the 10 years he had it but it did use (burn) a bit so he was effectively always topping up the additives etc.

 

As you say, not a gamble I'd want to take, depending on the value / use of the engine.

[Tony Brooks]

To add to what I said above.

 

Some marinisers fit a calorifier thermostat to control the flow through the calorifier, but most, including Beta, do not, so they rely on the closed engine thermostat to "force" coolant through the calorifier coil. This is done by taking the hot coolant out connection from the engine side of the engine thermostat, typically from the cylinder head. For some reason, some/a few fitters make the hot out connection on the skin tank side of the engine thermostat, which presents the opportunity for the skin tank and large bore cooling pipework to "short circuit" the calorifier and that could well cause cool domestic water and a long calorifier warm-up time.

[T_i_m]

48 minutes ago, Tony Brooks said:

To add to what I said above.

 

Some marinisers fit a calorifier thermostat to control the flow through the calorifier, but most, including Beta, do not, so they rely on the closed engine thermostat to "force" coolant through the calorifier coil. This is done by taking the hot coolant out connection from the engine side of the engine thermostat, typically from the cylinder head. For some reason, some/a few fitters make the hot out connection on the skin tank side of the engine thermostat, which presents the opportunity for the skin tank and large bore cooling pipework to "short circuit" the calorifier and that could well cause cool domestic water and a long calorifier warm-up time.

Interesting and thanks again for the explanation Tony.

 

So, I would be looking for a high / head level water pipe coming from the engine pre thermostat with the return going to anywhere in the return path from skin tank etc?

 

eg. The ideal NB setup would be like a traditional car engine based cabin heater where that cct is directly fed pre stat?

 

 

[Tony Brooks]

21 minutes ago, T_i_m said:

Interesting and thanks again for the explanation Tony.

 

So, I would be looking for a high / head level water pipe coming from the engine pre thermostat with the return going to anywhere in the return path from skin tank etc?

 

eg. The ideal NB setup would be like a traditional car engine based cabin heater where that cct is directly fed pre stat?

 

 

 

Exactly, although some claim it will slow down the warm-up of the engine, but after 60 year I see no significant signs of it occurring on run-of-the-mill boat engines, so I ignore them.

 

Further info. The reason 60 to 70 C stat are fitted to marinised engines is that on direct raw water cooled engines, anything hotter will encourage the deposit of salt or minerals on the inside of the water jacket in the head. This causes localised overheating, distortion and cracks. On skin tank cooled engines it keeps the temperature of the domestic water at a less dangerous level, but I would rather have it hot and use a thermostatic mixing valve to prevent scalding. That also reduces the hot water you use a bit.

[T_i_m]

3 minutes ago, Tony Brooks said:

 

Exactly, although some claim it will slow down the warm-up of the engine, but after 60 year I see no significant signs of it occurring on run-of-the-mill boat engines, so I ignore them.

 

Further info. The reason 60 to 70 C stat are fitted to marinised engines is that on direct raw water cooled engines, anything hotter will encourage the deposit of salt or minerals on the inside of the water jacket in the head. This causes localised overheating, distortion and cracks. On skin tank cooled engines it keeps the temperature of the domestic water at a less dangerous level, but I would rather have it hot and use a thermostatic mixing valve to prevent scalding. That also reduces the hot water you use a bit.

Yeah, if you consider how little volume of water is likely to be in the heater circuits and I also believe it keeps you safer from the likes of legionella etc.

 

[Colecraft Sunflower]

It could be simply that the flow and return taps on the engine block are closed. 

[plato]

His calorifier has probably got a mixing valve on it . May be worth checking that the temperature is not turned right down ? 

[LadyG]

8 hours ago, dmr said:

 

I did read (on the www 😀) of a farmer in America who never changed the oil on his new tractor and claimed that the money saved on services more than compensated for the slightly shorter life of the engine.  A high risk approach but interesting. 

I changed my engine oil at 250 hours but not the filter, [dont ask], so it sounds as though they are pretty long lived and it won't do long term damage, plus I've saved £16 for an oem filter!

Edited May 3 by LadyG

[T_i_m]

1 hour ago, Colecraft Sunflower said:

It could be simply that the flow and return taps on the engine block are closed. 

I guess it could be as I'm not really sure if when he says 'cold' he means cold or just 'not very hot' or 'not hot enough for a shower'.

 

Depending on the valve it could be that they are closed but not fully, if the hot water is just not 'as hot as is expected'?

36 minutes ago, LadyG said:

I changed my engine oil at 250 hours but not the filter, [dont ask], so it sounds as though they are pretty long lived and it won't do long term damage, plus I've saved £16 for an oem filter!

With the filters I believe they slowly block meaning they actually filter finer particles when old. The issue is them blocking completely and then any bypass opening and then you get no filtration at all. ;-(

[Tony Brooks]

40 minutes ago, LadyG said:

I changed my engine oil at 250 hours but not the filter, [dont ask], so it sounds as though they are pretty long lived and it won't do long term damage, plus I've saved £16 for an oem filter!

 

Are you aware that most modern oil filters have a bypass valve inside them so that if they clog, unfiltered oil and any particles it contains will be recirculated around the engine? This is likely to accelerate wear. If you must save money on servicing, I would suggest that it would be better to change the filter and leave the old oil in use until the next service. The new filter will clean up the old oil to a degree, and the oil additive pack is likely to still have some reserves of protection.

[T_i_m]

3 minutes ago, Tony Brooks said:

 

Are you aware that most modern oil filters have a bypass valve inside them so that if they clog, unfiltered oil and any particles it contains will be recirculated around the engine? This is likely to accelerate wear. If you must save money on servicing, I would suggest that it would be better to change the filter and leave the old oil in use until the next service. The new filter will clean up the old oil to a degree, and the oil additive pack is likely to still have some reserves of protection.

I think I have been advised (here) that on my mates Beta 50 the oil filter is reasonably accessible and above the general static oil level meaning it should be a fairly easy / clean job to change (where 'easy' probably means about the same as it does with most NB jobs). 😉 

1 hour ago, plato said:

His calorifier has probably got a mixing valve on it . May be worth checking that the temperature is not turned right down ? 

I believe he has mentioned that the shower is 'thermostatic'?

[LadyG]

On 03/05/2025 at 21:24, Tony Brooks said:

 

Are you aware that most modern oil filters have a bypass valve inside them so that if they clog, unfiltered oil and any particles it contains will be recirculated around the engine? This is likely to accelerate wear. If you must save money on servicing, I would suggest that it would be better to change the filter and leave the old oil in use until the next service. The new filter will clean up the old oil to a degree, and the oil additive pack is likely to still have some reserves of protection.

Good plan, I 'll get the oil changed as soon as I can get to civilisation, I'm not sure I can manage the filter myself,, that's why I left it rather than for economy

[Tony Brooks]

2 minutes ago, LadyG said:

Good plan, I 'll get the oil changed as soon as I can get to civilisation, I'm not sure I can manage the filter myself,, that's why I left it rather than for economy

 

Whilst I agree that the initial unscrewing oil filters by hand can be difficult, the location of the filters on modern engines, unless the boat builder/fitter was a prat, usually makes it easy to get a tool on it. Some tools are easier to use than others, but you may well have a suitable tool that you use to unscrew the tops of glass jars. This is a rubbery strap in a plastic handle, shaped so you pull the strap though the handle to tighten it and as you push/pull the handle the strap tightens. The "bottom" of modern spin on filters tend to be shaped to allow such tools greater grip, so don't fit any tool too far up the filter. I use a large pair of water pump/gland nut pliers, but such things are not worth buying just for filters, there are cheaper tools available.

 

Remember to oil the seal on the new filter before fitting it by hand - no tools to tighten.

[blackrose]

I find those rubber strap filter tools tend to slip on filters and the chain ones crush them.

 

I'm sure it's my fault for doing filters up too tightly when I fit them. On several occasions I've had to knock a big screwdriver through the filter to get it undone!

 

I once removed an oil filter from a honda car and it had a big nut shape at the end of the steel pressing so you could just put a spanner or a socket on it. Made me wonder why they're not all made like that? I guess people like me would do them up too tightly. 

Edited May 9 by blackrose

[Tony Brooks]

32 minutes ago, blackrose said:

I find those rubber strap filter tools tend to slip on filters and the chain ones crush them.

 

I'm sure it's my fault for doing filters up too tightly when I fit them. On several occasions I've had to knock a big screwdriver through the filter to get it undone!

 

I once removed an oil filter from a honda car and it had a big nut shape at the end of the steel pressing so you could just put a spanner or a socket on it. Made me wonder why they're not all made like that? I guess people like me would do them up too tightly. 

 

Unless they have altered it over the last very few years, the instructions on spin on filter say, oil the rubber seal, tighten until the seal contacts the face, tighten a further half turn by hand (I think it is half, but might be a quarter or three quarters, so check). I am sure may people, including myself and others who should know better do overtighten them to a degree for fear of leaks or falling off, but the self loosening is often caused, I think, by failure to oil the seal so it stretches rather than slides on the face, it then unscrews the filter a little when vibrated or heated and cooled.

[T_i_m]

2 hours ago, blackrose said:

I find those rubber strap filter tools tend to slip on filters and the chain ones crush them.

I think one of the chain tools is one of the tools I've had the longest and I can't remember ever completely crushing a filter with it (not saying I haven't, just that I can't remember) but I agree it can get 'stuck in' if the filter is particularly tight. No issue unless you are going to refit the filter?

 

I also have a pair of large pump pliers when you can get at the filter from the side and it's particularly stuck.

 

Daughters Corsa had a upturned filter body with a large nut moulded into the end (that I bought a socket to fit) and it was easier to reach near the top / front of the engine than the dipstick. 😉

 

The worst access wise was her Transit Connect as that was up the back of the engine. She was underneath the van, being careful removing the filter and planning an exit path for it when her business partner sort of pushed her out of the way, pulled the filter off and promptly tipped it's contents into the upturned sleeve of his jacket. 

 

'Fools rush in ...'. 😉