Water cylinders

[Ian Gardiner]

Hi,

 

I have just had a new Webasto water heater fitted on my narrowboat, Mave. I bought a cylinder (calorifier) for it which is open vented. I have been told that it is not suitable and that I will need a pressurised cylinder. Does that sound right to everyone on here ?

 

Cheers

 

Ian  

[Tony Brooks]

I don't see how a calorifier supplied for a boat can be open vented, so is this cylinder a proper marine calorifier or an indirect domestic cylinder? If the latter, it may well not be strong enough to cope with the 30 to 60 psi internal pressure from the domestic water pump.

 

If it really is a marine calorifier then it should be fine but make sure it is fitted with a PRV AND expansion vessel.

Edited October 7, 2021 by Tony Brooks

[Alan de Enfield]

3 minutes ago, Tony Brooks said:

If the latter, it may well to be strong enough to cope with the 30 to 60 psi internal

 

Is there a NOT missing from your sentence ?

[Ian Gardiner]

Hi Tony,

 

thanks for that. It was just a cylinder I bought from Cylinders2go. I did ask for one suitable for use on a boat system, but the one supplied was 'open vented' - so maybe shouldn't be classed as a calorifier. Do you think it's not suitable for a marine system, then?

 

Thanks

[Tracy D'arth]

Not suitable unless it is passed to 4 bar pressure minimum.

[Tony Brooks]

24 minutes ago, Ian Gardiner said:

Hi Tony,

 

thanks for that. It was just a cylinder I bought from Cylinders2go. I did ask for one suitable for use on a boat system, but the one supplied was 'open vented' - so maybe shouldn't be classed as a calorifier. Do you think it's not suitable for a marine system, then?

 

Thanks

 

I have just had a quick peep at their website and it does not even give the grade  for its cylinders. The grade is related to the head, and thus pressure, the cylinder is designed to work with. There is no information about the test or even operating pressure or head.

 

I think it is an ordinary domestic indirect cylinder so is unlikely to be suitable, but without the vital specifications hoe can anyone tell?

 

As you seem to have bought it then if you set your water pump cut-out pressure to 15psi or less and put up with the low pressure, then get a 1.5 bar PRV and finally fit an expansion tank also pressurised to 15 psi, it may last you a number of years but doing so is totally at our own risk. It could just as easily spilt in days or weeks. I can not advise this course of action.

 

 

 

 

[Ian Gardiner]

OK, thanks all. Back to the drawing board. Can anyone advise me of a good calorifier to use please. I want as large a tank as possible as we have a (small) bath on the boat as well

 

Thank again

[Tony Brooks]

See this topic

Reliable calorifier suppliers?

Edited October 7, 2021 by Tony Brooks

[Ian Gardiner]

Thanks for your help Tony. I just spoke to Trevor at Cylinders2go and he says as my tank is stainless steel it will run up to 3 bar pressure if I "run it unvented" with a PRV and expansion vessel.

 

Would you agree with that ?

[BEngo]

How long are they prepared to warrant it if it is being used at 3 bar?  If it is at least 12 months then I would give it a go.  Otherwise I would get a certified marine device with a safe working pressure and fit that, with a PRV set to 0.5 bar less  than SWP and an expansion vessel pressurised to the same pressure..

N

[Jen-in-Wellies]

25 minutes ago, Ian Gardiner said:

Thanks for your help Tony. I just spoke to Trevor at Cylinders2go and he says as my tank is stainless steel it will run up to 3 bar pressure if I "run it unvented" with a PRV and expansion vessel.

 

Would you agree with that ?

What if he is saying this just to get you to keep it and not have it returned and refunded? If it does split in a years time you have no come back and a very wet boat. Get a proper calorifer from someone who knows what that means and is certified to the pressures typically used on boats.

 

[Tony Brooks]

26 minutes ago, Ian Gardiner said:

Thanks for your help Tony. I just spoke to Trevor at Cylinders2go and he says as my tank is stainless steel it will run up to 3 bar pressure if I "run it unvented" with a PRV and expansion vessel.

 

Would you agree with that ?

 

Not unless he told you the test pressure. Please stop asking me to confirm what others have told you when you only supply partial specifications. I have given my opinion based on such information as you have chosen to disclose, I can't do more.

[Ian Gardiner]

Oh, sorry. I'm happy to disclose any information (I've attached a pic). It says test pressure 6 Bar, so I think I'll be good to go.

 

Thanks for your help anyway

20210426081345510.pdf

[Tracy D'arth]

In the end it is up to the OP to make his decision.  We do not bully folk on here but he has had others' opinions to consider.

[Ian Gardiner]

Hi Tracy,

 

Sorry, I'm new to this forum malarky. Opening Poster ! Just looked it up !!

 

Thanks for your help

[Ian Gardiner]

In this case does anyone have any recommendations for reliable installation companies. Last post, I promise

 

 

Thanks all

[Tony Brooks]

28 minutes ago, Ian Gardiner said:

Oh, sorry. I'm happy to disclose any information (I've attached a pic). It says test pressure 6 Bar, so I think I'll be good to go.

 

Thanks for your help anyway

20210426081345510.pdf 42.84 kB · 7 downloads

 

In that case I think it will be OK with a typical 2.5 to 3 bar water pump. PRV at least 5PSI (10 is better) above pump cut out pressure but not much higher, plus the expansion vessel pressurised to the pump cut out pressure.

[Ian Gardiner]

Brilliant advice. Thank you

[Tracy D'arth]

4 minutes ago, Ian Gardiner said:

In this case does anyone have any recommendations for reliable installation companies. Last post, I promise

 

 

Thanks all

A marine plumber not a domestic one.  Ever,.  Domestic guys are generally clueless about the requirements of boats.

 

I don't know the Notts area well, ask other boaters, chandlers and marinas locally for recommendations and see if any agree with each other!

[Tony Brooks]

12 minutes ago, Ian Gardiner said:

Hi Tracy,

 

Sorry, I'm new to this forum malarky. Opening Poster ! Just looked it up !!

 

Thanks for your help

 

Don't apologise. Those of us who have done the job know many people don't have a clue about what is important and what is not, and this is not helped by the quality of advice one often gets from essentially sales people.

 

I always feel a little vulnerable when being asked for advice that is not best practice because if something went wrong, in theory my past would lead a court to consider me an expert and as such I am expected to have a higher degree of care than a lay person.

[Detling]

Boat calorifiers are built to withstand high pressures and most have two or more heating coils, one for the engine coolant to heat the water when the engine is running, and the other, for in your case the webasto to heat the water. They usually run at 3 bar most domestic tanks are designed for about 0.5 bar.

[Split Pin]

Most domestic calorifiers are of the indirect vented type, the cold water feed is from a seperate stoarage tank, and they have a vent pipe back to the header tank, these are typically rated at 10 mt head of water which equates to 1Bar or 15 PSI.

 

 

It is possible to use a vented type in a marine situation, but the system need to work at the appropriate pressure.

 

Steven

Edited October 7, 2021 by Split Pin

[dave moore]

Trevithicks are a long established boatyard in Nottingham with a good reputation. They may be able to help.

[Alan de Enfield]

11 minutes ago, dave moore said:

Trevithicks are a long established boatyard in Nottingham with a good reputation. They may be able to help.

 

 

Certainly good at painting, blacking and building wooden boats, I don't know about their capabilities at plumbing.

 

 

[MtB]

5 hours ago, Ian Gardiner said:

Thanks for your help Tony. I just spoke to Trevor at Cylinders2go and he says as my tank is stainless steel it will run up to 3 bar pressure if I "run it unvented" with a PRV and expansion vessel.

 

Would you agree with that ?

 

If you google the phone number on cylinders2go.co.uk it is the same as a whole load of other websites/URLs with similar sorts of names.

 

They all seem to lead back to Telford Cylinders who are good, honest and well-regarded fabricators of copper and stainless cylinders for domestic dwellings, but I suspect they have little or no appreciation of the idiosyncrasies of the marine cauliflower market.