Disaster! help!

[Dave_P]

So there we both were, sitting in my boat, putting the world to rights when my 6th sense pricked up. The faint sound of the fresh water pump going off. Now this does sometimes happen a half hour or so after using a tap. I don't know why. This time, however, something didn't sound right about it. I hadn't had a tap on in a while and what's more, hadn't it just gone off 5 minutes ago?

 

We spent the next hour or so listening to the pump come on every few minutes and discussing possible reasons. My friend insisted it was just because my tank was empty, the pump was trying unsuccessfully to restore pressure to the system.

 

One snag with this idea though - I'd only filled my tank a couple of days earlier so it should have been nearly full. It was dark and cold by now and neither of us fancied clambering down the gunwales to check the tank levels. We decided to turn the pump off completely and wait until morning to investigate further.

 

In the morning I had to eat humble pie. The tank was empty! I reasoned that the hose hadn't been in properly when filling and the water I'd seen spilling over the front deck wasn't from the full tank but was just the hose water splashing about. I made a mental note to be more careful with such things in the future.

 

 

Overall I was relieved that my pump wasn't playing up but now had a problem filling my tank since the taps had all frozen solid. All except one. The one furthest away, which my hose wouldn't reach to. I needed a longer hose so spent all morning trawling the bargain shops for a cheap hose to extend mine with and finally hit the jackpot in Home Bargains. Yay!

 

All well that ends well right? Well no. Once the tank had filled a bit, we turned the pump back on and found it doing just the same thing as yesterday. "Maybe there's air in the system?" "Maybe it's just because it's filling?" "I'm sure it will settle down in a bit?". All a bit hopeful really, I'm sure you'll agree.

 

Then a sort of Eureka moment. I'd had the immersion on for about 25 minutes. More than enough for a bowl of hot water but the water only ran hot for a few seconds, then went cold. Nearly the whole day had passed and it was getting dark again, but, with the help of torchlight, I peered under my back deck to have a look at the calorifier. Or what was left of it! Water was still pouring from various bursts around the cylinder, as we were still filling the tank from the other end. If the engine bilge was much deeper with water, you could have swam in it!

 

As I type, I've now turned off the main stop cock to the water tank, leaving me with no running water. On the plus side, my tank is now completely full

 

Obviously (?) I'll need a new calorifier now, but my concern is getting it out. I'm 6'2" and 18 stone (it's all muscle - promise) and I can't fit down to the calorifier. It's in the engine bilge, sort of between the engine and the cabin bulkhead. I reckon a smaller person could get down there but I'm not convinced that there's space to pull the cylinder out through. Is this likely? Would a reputable builder such as Calcutt build a boat where you'd have to remove the engine first, in order to remove the calorifier? In other words, will this job cost me c.£500 or £1000+??

 

Thanks for reading.

[Athy]

Couldn't hav ebloomin' well happened in July, could it? I hope you get it sorted soon. If the calorifier won't come out, perhaps an instant gas heater could be installed, if they are still legal? Might work out easier and cheaper in the end.

[Dave_P]

Couldn't hav ebloomin' well happened in July, could it? I hope you get it sorted soon. If the calorifier won't come out, perhaps an instant gas heater could be installed, if they are still legal? Might work out easier and cheaper in the end.

 

I had thought of that, but wouldn't that involve cutting another hole in my roof, plumbing in new pipes, etc. Do you think it would be cheaper than yanking the engine out? I do quite like the idea of an instant heater though. I have a long term plan to install a full length bath which simply wouldn't work with a 10 gallon calorifier - or whatever it is.

 

I also like that I can heat my calorifier by immersion heater, alde boiler, or engine. Not an option with Morco or similar.

[Keith M]

It will not be the first time the calorifier was fitted before the engine

could the bulk head be cut and removed at way

 

Keith

[Troyboy]

I'm sure the calorifier will come out without removing the engine but a few parts might need to be removed for sufficient clearance . Cost will depend on the size of the calorifier as size does matter in this case . As Athy has stated would be a nicer job in July than January .

[Chris Pink]

The old calorifier will come out ok because it's fairly bendy and it doesn't matter whether it gets distorted. While you are doing that you'll be able to work out whether the new one ( which may be a different size) will go in.

 

It is impossible with words to ascertain or help with getting it through the space as this is a complex issue ( as the PG Tips ads illustrated )

 

Lifting the engine isn't a difficult job for someone 6'2" all muscle but that's getting a bit previous.

[Bobbybass]

Probably silly idea :

 

I wanted extra hot water...so I fitted a second calorifier...with one filling the second one.

Gives me 2 immersion heaters...and elements for extra fast water heating.

 

Is there space for 2 smaller ones....that you can get through T'ole ?

Edited January 21, 2013 by Bobbybass

[trackman]

I agree with Chris, the issue's not whether the old one will come out, that can always be arranged, even if it means hacking the thing to bits! The big question will be can you get a new one in without damaging it? Getting the old one out will give you some clues about getting a new one in. I'd strongly recommend keeping a calorifier if you can though. Having had both systems, a calorifier and an instant gas water heater, on different boats, I'd be very reluctant to go back to the gas heater for many reasons.

 

Mine failed last year. It was a difficult job to change it, and cost around £500 doing it myself. That included the new calorifier, about £60 for an expansion vessel (EV) on the hot side of the new cylinder and various plumbing bits and pieces required. There was no EV fitted by the original builder but the calorifier manufacturer (Surecal) has lately decided that many failures are caused by not having one. They will no longer guarantee their calorifiers if no EV is fitted apparently. I also added some isolation valves to certain connections that didn't have one, but should have! These bits did bump up the cost a bit, but I don't think I could have got away with less than £450 even if I hadn't added these.

 

Ours is under the bed and partially below a wardrobe, so pretty difficult to access: not as bad as yours sounds though! I'd recommend fitting a calorifier that's the same as the old one as it does make life far simpler when connecting things back together.

 

Good luck!

 

 

[Athy]

Probably silly idea :

 

I wanted extra hot water...so I fitted a second calorifier...with one filling the second one.

Gives me 2 immersion heaters...and elements for extra fast water heating.

 

Is there space for 2 smaller ones....that you can get through T'ole ?

You must be s student of Webb of the LNWR and Johnson of the Midland Railway - exponents of compound expansion in locomotives! I hope your design owes more to Johnson, as Webb's compound engines rarely worked properly.

(For overseas readers, think Chapelon).

[Dave_P]

Thanks for all the advice guys! I now know that my calorifier doesn't have an expansion tank. It seems that this is very common. As I'm not very handy like some of you are, I'm looking at having the job done for me. I'm looking at around £900 all in. Which ain't good! Better news is that I should have running cold water again by the end of the day. Again, looking for the silver linings, not being able to shower on the boat should encourage me to visit the gym more often. To fine tune my magnificent physique Chris!

 

Probably silly idea :

 

I wanted extra hot water...so I fitted a second calorifier...with one filling the second one.

Gives me 2 immersion heaters...and elements for extra fast water heating.

 

Is there space for 2 smaller ones....that you can get through T'ole ?

 

maybe a very tall and thin one will fit.

[Paul C]

Why did the original burst? Was it frost damage, or overheating due to no water (I thought immersion elements had a thermostat on them, and in any case you should have had a pressure relief valve if you don't have the expansion tank; and if you do, then still need a PRV but could be set at a higher pressure).

 

Definitely worth getting to the bottom of this before/during installing the replacement.

[Dave_P]

Why did the original burst? Was it frost damage, or overheating due to no water (I thought immersion elements had a thermostat on them, and in any case you should have had a pressure relief valve if you don't have the expansion tank; and if you do, then still need a PRV but could be set at a higher pressure).

 

Definitely worth getting to the bottom of this before/during installing the replacement.

 

There is a pressure release valve but no expansion tank. As far as I can make out, the rapid changes in pressure when repeatedly heating water and then using the hot water thus rapidly cooling the calorifier are likely to cause failure of the tank over time. The pressure release valve seems to function mainly as a outlet in case the water pump gets jammed on.

 

From a bit of asking around, this is a fairly common occurence where no expansion tank is fitted. Are you guys also aware of this?

[Paul C]

If no expansion tank is fitted, then the pressure release valve accommodates the increase in pressure of the water, due to the increase in its volume, due to the increase in its temperature, when the water is heated.

 

I believe a calorifier can wear out and split, if this is the case with yours then it surely is just bad luck, it could happen at any time.

[blackrose]

 

 

I also like that I can heat my calorifier by immersion heater, alde boiler, or engine. Not an option with Morco or similar.

 

So why not have both?

 

I have a calorifier and a gas water heater and control which supply I use with a manual lever L-port valve.

[RLWP]

Webb's compound engines rarely worked properly.

 

I'll bite. Please explain the words 'rarely' and 'properly' in your statement. I suggest you use 'Jeanie Deans' eight years of work on the Premier Line's Scotch Diner, and the long life of the 0-8-0 compound goods engines to illustrate your point

 

Richard

[MtB]

From a bit of asking around, this is a fairly common occurence where no expansion tank is fitted. Are you guys also aware of this?

 

I'm very much aware of this problem and used say so in calorifier threads regularly. It's metal fatigue caused by the constant wide pressure variations in my opinion. An expansion vessel extends the life of the cylinder but does not eliminate the problem, mainly because they lose their nitrogen charge and no-one ever replenishes it so they stop working. Copper unvented cylinders have become totally obsolete in domestic houses for this reason.

 

I usually get argued down on this point so I've stopped mentioning it these days!

 

MtB

[Athy]

I'll bite. Please explain the words 'rarely' and 'properly' in your statement. I suggest you use 'Jeanie Deans' eight years of work on the Premier Line's Scotch Diner, and the long life of the 0-8-0 compound goods engines to illustrate your point

 

Richard

No, I think it more likely that you will use them to illustrate yours. Doubtless my having been born and brought up in strictly Midland territory coloured my remarks. I have, however, read of Webb's 4-4-0 compounds (can't remember which class) having severe co-ordination problems. I do not recall having heard of the Johnson (and, I think Deeley) Midland compounds having any such deficiencies.

I had no idea that the LNWR 0-8-0 goods engines (a couple of which I saw working at the end of their lives) were compounds. Indeed, a glance at my 1961 Ian Allen Combined Volume shows that they were described as superheated, with no mention of "compound". Are you sure about this?

[Dave_P]

So why not have both?

 

I have a calorifier and a gas water heater and control which supply I use with a manual lever L-port valve.

 

Simple - I can't afford it.

[Dave_P]

If no expansion tank is fitted, then the pressure release valve accommodates the increase in pressure of the water, due to the increase in its volume, due to the increase in its temperature, when the water is heated.

 

I believe a calorifier can wear out and split, if this is the case with yours then it surely is just bad luck, it could happen at any time.

 

Look at it this way - my pump kicks in at 0.9 bar and pressurises to 1.7 bar. Before turning on my immersion this means that I have water in my calorifier at about 10 degrees C at 1.7 bar. When I heat my water to, say, 70 degrees C, the pressure in my calorifier rises, let's say to 2.7 bar. The pressure release valve needs to be set higher than this so it doesn't vent every time I heat the water. Let's say it's set to 3.0 bar. Under normal usuage then, the calorifier has to undergo considerable pressure changes so it will expand and contract. It's not hard to see how this could lead to a split where there is a slight imperfection in the copper.

 

Are all calorifiers pressure tested before they are sold? No! Are boat builders likely to go for the cheapest option (no expansion tank, untested cylinder)? Yes!

[Paul C]

The problem is its liquids though, which are (almost) incompressible. A small rise in temperature will result in a tiny increase in volume, but a massive increase in pressure. Hence, the PRV will be working all the time, 'holding' the calorifier below the PRV's opening pressure eg 3 bar.

 

Expansion tanks work in a different fashion - they allow a variation in the volume of the liquid, thus the pressure rises and falls more gradually. Whether this prolongs the life of a calorifier, I don't know.

[Bobbybass]

I'm very much aware of this problem and used say so in calorifier threads regularly. It's metal fatigue caused by the constant wide pressure variations in my opinion. An expansion vessel extends the life of the cylinder but does not eliminate the problem, mainly because they lose their nitrogen charge and no-one ever replenishes it so they stop working. Copper unvented cylinders have become totally obsolete in domestic houses for this reason.

 

I usually get argued down on this point so I've stopped mentioning it these days!

 

MtB

 

Nitrogen charge..?...

 

Every year..I just top mine up with my tyre foot pump ?

Edited January 21, 2013 by Bobbybass

[Dave_P]

The problem is its liquids though, which are (almost) incompressible. A small rise in temperature will result in a tiny increase in volume, but a massive increase in pressure. Hence, the PRV will be working all the time, 'holding' the calorifier below the PRV's opening pressure eg 3 bar.

 

Expansion tanks work in a different fashion - they allow a variation in the volume of the liquid, thus the pressure rises and falls more gradually. Whether this prolongs the life of a calorifier, I don't know.

 

Well clearly it does!

 

Nitrogen charge..?...

 

Every year..I just top mine up with my tyre foot pump ?

Sounds sensible. how do you know it's the right pressure though?

[nb Innisfree]

When the calorifier heats up the water expands by about 2% by volume which on a 50 litre cal equals about 1 litre, with no exp tank or accumulator it has nowhere to go so it transfers the expansion hydraulicly to the cyl and putting a strain on it until eventually the PRV operates. If there is an accumulator or exp tank they will absorb that expansion with a cushioning effect.

Edited January 21, 2013 by nb Innisfree

[jonathanA]

I'm very much aware of this problem and used say so in calorifier threads regularly. It's metal fatigue caused by the constant wide pressure variations in my opinion. An expansion vessel extends the life of the cylinder but does not eliminate the problem, mainly because they lose their nitrogen charge and no-one ever replenishes it so they stop working. Copper unvented cylinders have become totally obsolete in domestic houses for this reason.

 

I usually get argued down on this point so I've stopped mentioning it these days!

 

MtB

 

hi MtB,

 

so presumably my stainless steel heatrae cylinder at home isn't about to dump 250 litres of water through my ceiling !.

 

Are the newer surecal calorifiers not stainless as well ?

[RLWP]

No, I think it more likely that you will use them to illustrate yours. Doubtless my having been born and brought up in strictly Midland territory coloured my remarks. I have, however, read of Webb's 4-4-0 compounds (can't remember which class) having severe co-ordination problems. I do not recall having heard of the Johnson (and, I think Deeley) Midland compounds having any such deficiencies.

I had no idea that the LNWR 0-8-0 goods engines (a couple of which I saw working at the end of their lives) were compounds. Indeed, a glance at my 1961 Ian Allen Combined Volume shows that they were described as superheated, with no mention of "compound". Are you sure about this?

 

Curiously, there is railway history before 1961

 

There were two classes of 0-8-0 compound, three cylinder 'A' class and four cylinder 'B' class. There were built after the experimental simple, two cylinder 0-8-0 at a time when the LNWR had given up building 0-6-0s for goods use (compare with MR practice)

 

Webb's 4-4-0 compounds (Jubilees and Alfred the Greats) were pretty successful passenger locomotives

 

What you are repeating (incorrectly) are the apocryphal stories, probably spread by Ahron,s about the 1880s 2-2-2-0 three cylinder passenger locomotives. For example:

 

Webb's name is chiefly associated with compound locomotives, of which he was a staunch advocate. First of all he favoured three-cylinder compounds, with two high- and one low-pressure cylinders, and then four-cylinder compounds, with two high- and low-pressure cylinders. The. writer has a friend with a good memory, backed by well-kept note-books, who rode on and behind three-cylinder compounds at the turn of the century. This gentleman assures him that, although there undoubtedly were starting difficulties, these have been greatly exaggerated by modern writers. The much-cherished story that these engines had to be started with pinch-bars had very little foundation in fact.

 

The late E. L. Ahrons, who was by no means "pro-L.N.W.R.," specifically stated on page 247 of "The British Steam Railway Locomotive from 1825 to 1925 " that on a few occasions the high- and low-pressure driving wheels of those engines fitted with slip-eccentrics to the low-pressure valve gear revolved in opposite directions when startmg. There is no doubt at all that if this had been anything like a common occurrence he would have said so.

 

http://www.steamindex.com/people/webb.htm

 

There are two very good reasons why the early compounds didn't last long. Firstly, in the early stages of learning about compounds, Webb picked the wrong arrangement for a three cylinder compound, meaning the two putside cylinders were only just big enough to lift a train. The Smith arrangement used by the Midland was the right choice as it could be used as a three cylinder simple for starting. Secondly, the massive growth in traffic around the turn of the last century meant that they were all too small for the work. Crewe were pretty pragmatic, so into the pot they went

 

Richard