Probably stupid questions about Narrowboat heating, boilers etc

[MtB]

We know...

 

 

 

MtB

[Southern Star]

Hi,

We live aboard and our Webasto is now 6 years old and heats hot water and rads, we also run it on kerro as this is a lot "cleaner" than red diesel

Now done 4500 + hours and its never been serviced as I see no reason to pull it apart to decoke it as it can't be coked cos it runs perfectly?

 

 

Best way to keep any auxiliary heater coke-free and working well is to run it at absolute maximum temperature for around 20-30 minutes once a fortnight or so, Winter and Summer.

[Lizzy]

Sorry to dig this up again, but I thought better than starting a new thread for my stupid questions.

 

I'm in the process of looking for a liveaboard boat. Some of my favourites have a solid fuel stove, but no central heating. From all I've read I think I'd probably go for fitting a webasto. So far so good.

 

But I am not sure about the hot water. Thrse boats have a calorifier heated through the engine. Would that be reused but then powered by the webasto? Also is this an either or? Or can it be heated by both optionally? I.e. When cruising use the engine and if not, use the central heating? What about the summer? Do you have to run heating solely for hot water?

 

I like to shower in the morning. How long does a calorifier typically need to heat up and how long does it hold the heat? Will cruising from day before be enough for a shower next morning?

 

I'm sure these are easy questions for a change

[Chewbacka]

Hi. If the calorifier has 2 heating coils you use one with the engine and the other with the boiler. If yours has only a single heating coil you would either replace the calorifier or possibly you can buy a second coil that replaces the immersion heater, that assumes you have an immersion heater to replace. I don't know how effective these replacement coils are.

 

If you plan to live aboard and rarely move the boat, then if you have a single coil calorifier and need to save money you could just use the boiler to heat the water.

 

You can arrange the plumbing so the boiler heats the hot water and not the rads or heats both. So no hot rads on a hot summer day.

 

A well lagged tank will be fine in the morning if it was full and hot the night before. But jjust to use simple numbers, if your hot water tank holds 50 litres and it was at 75c when you finished running the engine. However you draw off 30 litres during the evening - washing up, washing before bed etc, means you will have put 30 litres of cold water into the hot tank. This will cool the tank down. Though hot water sits on top of cold, overnight there will be a fair bit of heat conducting from the hot layer to the cold layer, so be prepared for a very cool if not cold shower in the morning.

[ditchcrawler]

We always finish cruising by 5pm and we have two showers from the tank the next morning when we get up, but we don't need to add any cold water. We also do the washing up in the evening after dinner.

[Lizzy]

Great thank you. I've been at Crick today and spoke to a number of suppliers of tanks, heating etc. They told me that it's fine to fit a coil into an existing calorifier. So this shouldn't be a problem. Phew.

[ditchcrawler]

Great thank you. I've been at Crick today and spoke to a number of suppliers of tanks, heating etc. They told me that it's fine to fit a coil into an existing calorifier. So this shouldn't be a problem. Phew.

Did they?

[Chewbacka]

This is what I was talking about above

It replaces the immersion heater

Edited May 29, 2016 by Chewbacka

[ditchcrawler]

This is what I was talking about above

It replaces the immersion heater

OK if you have an Immersion heater boss

[Chewbacka]

As I said above, you can only fit one of these "assumes you have an immersion heater to replace".

I don't know of another way of adding a second coil to an existing single coil heat exchanger. One could do it with a heat exchanger and a pump and controler, but it would probably end up costing as much as a new twin coil calorifier and need battery power as well.

 

Also if you are on shore power a lot you would not want to lose the immersion heater. However until the OP gives a better explanation of her requirements and what she has at the moment we can only offer possibilities which may or may not suit her.

Edited May 29, 2016 by Chewbacka

[Lizzy]

I see the point why this might not always be possble. It's a bit academic, since I don't even have a boat yet. I know what to look out for now.

[Chewbacka]

You also need to think very hard about where you will moor the boat if you intend to stay in London for work etc.

Moorings are very rare. Have a browse through these old topics.

 

http://www.canalworld.net/forums/index.php?showtopic=76945&hl=london+moorings#entry1588497

http://www.canalworld.net/forums/index.php?showtopic=76255&hl=london+moorings

 

CRT is looking to develop a London Mooring strategy which probably means they want less people living on the London waterways without a fixed mooring. In other words those that move location every couple of weeks. What I think they do want is short term visitors, and if staying on the more popular places, these will be paid for on a per night basis.

http://www.canalworld.net/forums/index.php?showtopic=84352&hl=london+moorings

 

The days of low cost London boat living are going, if not already gone.

[Lizzy]

So .... meanwhile I've got a boat and it has a Webasto Thermo Top C fitted. I thought that it can heat the water and/or the radiators as it was fitted right with the build of the boat. The surveyor also said that there is a way that it can heat the hot water, but not the radiators in the summer. But I can't work out how to set this. The only control I found is a little panel like this:

http://www.webasto.com/uploads/pics/marine-digital-timer-220.jpg

 

As far as I can see it can only switch on/off immediately or set a timer. How do I set it so that it doesn't heat the radiators, but only the hot water in the summer? Do I simply switch it on with the radiators turned off? It seems like quite a waste to do it this way.

[Chewbacka]

So .... meanwhile I've got a boat and it has a Webasto Thermo Top C fitted. I thought that it can heat the water and/or the radiators as it was fitted right with the build of the boat. The surveyor also said that there is a way that it can heat the hot water, but not the radiators in the summer. But I can't work out how to set this. The only control I found is a little panel like this:

http://www.webasto.com/uploads/pics/marine-digital-timer-220.jpg

 

As far as I can see it can only switch on/off immediately or set a timer. How do I set it so that it doesn't heat the radiators, but only the hot water in the summer? Do I simply switch it on with the radiators turned off? It seems like quite a waste to do it this way.

Probably there are some manual valves on the pipe work. Either a 3 way valve or a couple of on/off valves, but I can only guess.

So in winter you set it for both in summer you set it for hot water only.

If it was fitted by the boat builder I would hope the valves are labelled.

What ever you do, make sure you do not turn off the flow of water through the boiler, the hot water must be able to go somewhere or your boiler will overheat.

[MtB]

OK if you have an Immersion heater boss

 

 

AND if you don't want an immersion heater...

[Sea Dog]

So .... meanwhile I've got a boat and it has a Webasto Thermo Top C fitted. I thought that it can heat the water and/or the radiators as it was fitted right with the build of the boat. The surveyor also said that there is a way that it can heat the hot water, but not the radiators in the summer. But I can't work out how to set this. The only control I found is a little panel like this:

http://www.webasto.com/uploads/pics/marine-digital-timer-220.jpg

 

As far as I can see it can only switch on/off immediately or set a timer. How do I set it so that it doesn't heat the radiators, but only the hot water in the summer? Do I simply switch it on with the radiators turned off? It seems like quite a waste to do it this way.

Congratulations on your new boat! I hope you have many happy times together.

 

These things are not as clever or complicated as you're imagining. You can use it as normal using your controls with individual radiators 'switched off' at their valves. Your calorifier coil in the hot water tank needs to remain open so that the hot water in the heating circuit can flow and I'd suggest to also leave your bathroom radiator open too to maintain sufficient load. The heat you generate needs to go somewhere or the boiler will short cycle (cut in, cut out at short intervals) which does them no good. Listen for that happening and shut down once it starts by which time, if your system is properly set up, you'll have hot water. You'll soon get to know roughly how long to leave it on for. Note however, that in a twin coil hot water tank system, the engine usually heats via the bottom coil and the Webasto will heat via the upper coil. This means you'll only get half a tank of hot water using this method, so don't be surprised when the hot water runs out faster than when you're cruising.

[Lizzy]

Ah that's very good to know. Thanks very much. We haven't actually needed to switch it on yet after all, since we are cruising and the water was still really hot the next morning.

[toekneep]

I love this place. I have all the answers without asking a single question!

[MtB]

I love this place. I have all the answers without asking a single question!

 

 

The answers are the easy bit. Thinking of the right question is far harder.

 

In fact the drafting exactly the right question often makes the answer clear while doing it, I find!

[widebeamboy]

Congratulations on your new boat! I hope you have many happy times together.

 

These things are not as clever or complicated as you're imagining. You can use it as normal using your controls with individual radiators 'switched off' at their valves. Your calorifier coil in the hot water tank needs to remain open so that the hot water in the heating circuit can flow and I'd suggest to also leave your bathroom radiator open too to maintain sufficient load. The heat you generate needs to go somewhere or the boiler will short cycle (cut in, cut out at short intervals) which does them no good. Listen for that happening and shut down once it starts by which time, if your system is properly set up, you'll have hot water. You'll soon get to know roughly how long to leave it on for. Note however, that in a twin coil hot water tank system, the engine usually heats via the bottom coil and the Webasto will heat via the upper coil. This means you'll only get half a tank of hot water using this method, so don't be surprised when the hot water runs out faster than when you're cruising.

 

I'm no expert however the authorised Webasto expert who I use and trust would I believe suggest this was not a great thing to do and that the single bathroom rad would be insufficient load and constant/prolonged use in this manner will lead to issues with your Webasto. I might be completely wrong, he is a member on here so be interested to see his views.

[Robbo]

 

I'm no expert however the authorised Webasto expert who I use and trust would I believe suggest this was not a great thing to do and that the single bathroom rad would be insufficient load and constant/prolonged use in this manner will lead to issues with your Webasto. I might be completely wrong, he is a member on here so be interested to see his views.

Sounds like the Webasto would not be suitable for use for heating a boat then especially if you want it as a primary heating source.

[Sea Dog]

 

I'm no expert however the authorised Webasto expert who I use and trust would I believe suggest this was not a great thing to do and that the single bathroom rad would be insufficient load and constant/prolonged use in this manner will lead to issues with your Webasto. I might be completely wrong, he is a member on here so be interested to see his views.

I don't disagree that they need load or are likely fail prematurely - hence why you leave a rad in the circuit even in the summer when heating water and why the bit about listening for short cycling is important.

[howardang]

The fire came with the boat or I would have done

 

Is it practical to sell the existing stove and put the proceeds to one which has a back boiler?

 

Howard