Jump to content

How many coils dose my calorifier have?


Featured Posts

Hi everyone, now bare with me here as my know page of plumbing is basic at best, I currently have a horazontal calorifier which is providing my hot water from the raw water cooled engine, but I’d like to add a second heat source from the back boiler on my wood burner. Problem is am not sure whether I have a single or twin coil. Is there a way of telling by the amount of valve fittings on the tank (I have 5) or do I have to drain the system and remove the immersion and look inside? Any advice would be great. Cheers. Darren 

Link to comment
Share on other sites

A calorifier has a cold inlet and a hot outlet (2 connections so far)

It has an inlet and outlet for a heating coil (another 2 = 4 so far)

If it has an inlet and outlet for a second heating coil that would be another 2 = 6 total.

 

So if you only have 5 you only have 1 coil and the 5th connection is probably the PRV (pressure relief valve)

 

But do check both ends of the calorifier. Our horizontal calorifier has most of the connections at one end, but two at the other end being the second coil.

Link to comment
Share on other sites

3 minutes ago, Darrenroberts said:

Thanks for getting back to me so quickly, I’ve just had another look and do have two valves at the other end. So 5 at one end (with one having what looks like a draining valve) and two at the other end. 

And how many pipe do you have connected to it

Link to comment
Share on other sites

10 minutes ago, Darrenroberts said:

Thanks for getting back to me so quickly, I’ve just had another look and do have two valves at the other end. So 5 at one end (with one having what looks like a draining valve) and two at the other end. 

So that answers your question, you calorifier has two coils. Presumably the second set of connections are currently unused.

 

What you suspect is the draining valve is probably the pressure relief valve. Normally these have some sort of red knurled knob which can be used to open the relief valve - useful to check it is actually working and sometimes to clear an accumulation of scale that is making it dribble. Normally they are at the top, so they are not really a draining valve, just a spring loaded valve that will open if the pressure in the calorifier gets too high. Obviously when cold water in the calorifier is heated, it expands and increases the pressure. Without the relief valve the calorifier pressure might get too high and cause it to rupture.

Edited by nicknorman
Link to comment
Share on other sites

3 minutes ago, Darrenroberts said:

It appears all the valves are connected up? I’ll take some photos to clarify 

Perhaps there is already an alternative source of heat, eg a diesel heater such as a Mikuni, Eberspacher, Webasto etc. Or a gas heater like an Alde.

Oh yes it is a drain valve. The PRV must be Td off elsewhere.

It certainly looks as though you have another source of heating, but we can't tell what it is from the photos. You need to trace the pipes back. I suppose it is possible that both coils are connected to the engine in parallel, although that is not how it is normally done!

Link to comment
Share on other sites

2 minutes ago, nicknorman said:

Perhaps there is already an alternative source of heat, eg a diesel heater such as a Mikuni, Eberspacher, Webasto etc. Or a gas heater like an Alde.

No the only how water source is from the engine as a Plummer connected it when I bought the the boat. Could he of connected the engine too both coils? If there is two that is? 

7 minutes ago, nicknorman said:

Perhaps there is already an alternative source of heat, eg a diesel heater such as a Mikuni, Eberspacher, Webasto etc. Or a gas heater like an Alde.

Oh yes it is a drain valve. The PRV must be Td off elsewhere.

It certainly looks as though you have another source of heating, but we can't tell what it is from the photos. You need to trace the pipes back. I suppose it is possible that both coils are connected to the engine in parallel, although that is not how it is normally done!

Sorry I only just saw your full message, yeh the prv is td off at the top. So yeh mabey both coils are in use on the engine. 

Link to comment
Share on other sites

4 minutes ago, Darrenroberts said:

No the only how water source is from the engine as a Plummer connected it when I bought the the boat. Could he of connected the engine too both coils? If there is two that is? 

Sorry I only just saw your full message, yeh the prv is td off at the top. So yeh mabey both coils are in use on the engine. 

If so, it would be straightforward to modify the plumbing so only one coil was connected to the engine and the other to your back boiler.

Link to comment
Share on other sites

8 minutes ago, nicknorman said:

If so, it would be straightforward to modify the plumbing so only one coil was connected to the engine and the other to your back boiler.

Ok touch wood that is the case, otherwise the price of this job is going through the roof lol, thank you for all your advice, I can relax a little bit now. Cheers 

Link to comment
Share on other sites

Just wondering how you intend to circulate the hot water from the back boiler? I’ve no personal experience but I think thermo siphoning / gravity circulation through a calorifier doesn’t really work due to the restrictions of the coil. Or maybe you already have a pump?

Link to comment
Share on other sites

14 minutes ago, nicknorman said:

Just wondering how you intend to circulate the hot water from the back boiler? I’ve no personal experience but I think thermo siphoning / gravity circulation through a calorifier doesn’t really work due to the restrictions of the coil. Or maybe you already have a pump?

Yeh I’ll defiantly need a pump as my burner is at the front and the tank at the back I’ll never get the rize.....also it’s horizontal lol. I’ve been looking at jabsco 12v circulation pumps, the plastic body ones but there not cheep £180! I was Gunnaput two small rads in two as a heat sink. So A new calorifier will wreck my budget lol 

Link to comment
Share on other sites

8 hours ago, Darrenroberts said:

Yeh I’ll defiantly need a pump as my burner is at the front and the tank at the back I’ll never get the rize.....also it’s horizontal lol. I’ve been looking at jabsco 12v circulation pumps, the plastic body ones but there not cheep £180! I was Gunnaput two small rads in two as a heat sink. So A new calorifier will wreck my budget lol 

Yes the rads are a good idea as once the calorifier is up to temperature it won’t absorb any more heat and the back boiler might boil.

 

You could consider a Solarproject pump. Cheap and cheerful but seems to work well. I’ve got two of them but they aren’t on for long periods so can’t comment on the long term reliability. Quiet though. You could perhaps have two, one as a backup. Obviously if the pump fails you’ve got a problem with the water boiling so make sure you have pressure relief preferably overboard.

 

http://shop.solarproject.co.uk/catalog/product_info.php?products_id=29&osCsid=b492c94af351f9321701d88749629e35

 

 

Link to comment
Share on other sites

20 minutes ago, Boater Sam said:

I consider a solid fuel burning boiler that relies on an electric pump for any circulation to be an unsafe and dangerous installation based on 40+ years experience of heating systems and codes of practice.

I know what you mean, but plenty of folk seem to do so. I think it is OK if you have adequate means to expel boiling water / steam overboard. Being realistic about it, can you point to anyone who was injured on a boat by an overheating back boiler system caused by pump failure?

 

I have a vague long term plan of fitting a BB to run the rads (that are currently heated by the mikuni). It would have to be pumped because the rads are not installed with gravity circulation in mind. I would have two pumps, a main and a backup, with a temperature switch to start the backup and bring on a warning light or buzzer. With those Solarproject pumps being so cheap, it wouldn’t be costly.

 

OP could arrange for his 2 new radiators to gravity circulate and use a pump just to circulate through the calorifier.

Edited by nicknorman
Link to comment
Share on other sites

3 hours ago, Boater Sam said:

I consider a solid fuel burning boiler that relies on an electric pump for any circulation to be an unsafe and dangerous installation based on 40+ years experience of heating systems and codes of practice.

What would u use instead Sam? I have thought about pump failure I was wondering if I could add in a pressure/temp gauge to the pipe work on the flow some where near the back to monitor temperature, was also thinking of some train like steam release horn for emergency’s. I was gunna run the pressure release  to the engine bildge, the same place as where the calorifier blow out is? 

Link to comment
Share on other sites

28 minutes ago, Darrenroberts said:

What would u use instead Sam? I have thought about pump failure I was wondering if I could add in a pressure/temp gauge to the pipe work on the flow some where near the back to monitor temperature, was also thinking of some train like steam release horn for emergency’s. I was gunna run the pressure release  to the engine bildge, the same place as where the calorifier blow out is? 

The alternative is gravity circulation, at least for part of it (the radiators).

 

are you going to have sealed system with an expansion vessel, or the more normal header tank? If the latter, don’t forget the easiest way out for high pressure steam and boiling water is via the header tank, so be careful where you site it. If you are going for a sealed system I think that is potentially more dangerous and I would want both a “normal” pressure relief valve, and an “emergency” one. You have to bear in mind that a pressure relief valve that goes months or years without ever having to operate is likely to become gunged up and so not work just when you need it to. You should design not just for how the system will be when you install it, but also how it will be in 10 years time with corrosion and scaling.

 

Just remember that a jet of high pressure steam can easily take all your skin off. And then you die, slowly and rather unpleasantly.

Link to comment
Share on other sites

42 minutes ago, Darrenroberts said:

What would u use instead Sam? I have thought about pump failure I was wondering if I could add in a pressure/temp gauge to the pipe work on the flow some where near the back to monitor temperature, was also thinking of some train like steam release horn for emergency’s. I was gunna run the pressure release  to the engine bildge, the same place as where the calorifier blow out is? 

Your mention of a pressure release implies a sealed pressurised system which terrified me.

The thought of the volume of water in the heating system at a temperature above boiling point due to pressurisation being released into a confined space suddenly where it will turn instantly into live wet steam which will fill the volume of the boat instantly and scald any life form to death is a truly frightening idea.

DON'T DO IT.

 

There is no way of achieving close temperature and over temperature control on a solid fuel boiler in a boat.

 

I know that it is sometimes difficult to arrange a heat soak by gravity but it is the ONLY save way. Really you need a dump for the maximum output of the boiler, the calorifier is the ideal one failing that enough radiator area to cope with sufficient thermosyphon flow will do.

 

Calorifier is a non starter if horizontal,  the only way is to arrange the gravity pipework flow high enough from the boiler  to enable the return to run uphill back to the boiler return, not easy. The head of flow by gravity is very small, pipework needs to be large bore and direct with absolute minimum resistance to achieve a good result, not easy to calculate accurately.

 

The radiators can have the flow pipe up under the gunnel, the returns at lower level back to the boiler, no thermostatic valves either. Raising them up from the floor by a foot or more will help achieve circulation. Main flow and return need to be at least 22mm, preferably 28mm if the runs are anything other than short and direct. Bends rather than elbows.

 

There needs to be a constant rise in the flow pipe and a constant fall in the return back to the boiler with no dips, which more or less rules out plastic pipe. Never a good idea with solid fuel boilers anyway. Vents on all high points, drain/s on lowest point/s. Expansion and feed tank on a high point.

 

If you want to send me a layout diagram of the boat I can try and design for you.

 

Sam

Edited by Boater Sam
Link to comment
Share on other sites

7 minutes ago, Boater Sam said:

Your mention of a pressure release implies a sealed pressurised system which terrified me.

The thought of the volume of water in the heating system at a temperature above boiling point due to pressurisation being released into a confined space suddenly where it will turn instantly into live wet steam which will fill the volume of the boat instantly and scald any life form to death is a truly frightening idea.

DON'T DO IT.

 

There is no way of achieving close temperature and over temperature control on a solid fuel boiler in a boat.

 

I know that it is sometimes difficult to arrange a heat soak by gravity but it is the ONLY save way. Really you need a dump for the maximum output of the boiler, the calorifier is the ideal one failing that enough radiator area to cope with sufficient thermosyphon flow will do.

 

Calorifier is a non starter if horizontal,  the only way is to arrange the gravity pipework flow high enough from the boiler  to enable the return to run uphill back to the boiler return, not easy. The head of flow by gravity is very small, pipework needs to be large bore and direct with absolute minimum resistance to achieve a good result, not easy to calculate accurately.

 

The radiators can have the flow pipe up under the gunnel, the returns at lower level back to the boiler, no thermostatic valves either. Raising them up from the floor by a foot or more will help achieve circulation. Main flow and return need to be at least 22mm, preferably 28mm if the runs are anything other than short and direct. Bends rather than elbows.

 

There needs to be a constant rise in the flow pipe and a constant fall in the return back to the boiler with no dips, which more or less rules out plastic pipe. Never a good idea with solid fuel boilers anyway. Vents on all high points, drain/s on lowest point/s. Expansion and feed tank on a high point.

 

If you want to send me a layout diagram of the boat I can try and design for you.

 

Sam

Is there any reason not to have a gravity circulation radiator system augmented by a small pump to circulate through the calorifier?

Link to comment
Share on other sites

That is a reasonable alternative as I thought I had made clear. BUT the radiators need to soak up a reasonable percentage of the boiler output under all conditions which means that they cannot be turned off in summer whilst the pumped calorifier is used for hot water which may be a problem. To this end when I install such a system, rarely, I fit no valves to the radiators.

Link to comment
Share on other sites

1 minute ago, Boater Sam said:

That is a reasonable alternative as I thought I had made clear. BUT the radiators need to soak up a reasonable percentage of the boiler output under all conditions which means that they cannot be turned off in summer whilst the pumped calorifier is used for hot water which may be a problem. To this end when I install such a system, rarely, I fit no valves to the radiators.

Seems unlikely anyone would want to run a wood burning stove in summer just for hot water, when at least 50% of the heat goes into the room.

Link to comment
Share on other sites

1 hour ago, Boater Sam said:

Your mention of a pressure release implies a sealed pressurised system which terrified me.

The thought of the volume of water in the heating system at a temperature above boiling point due to pressurisation being released into a confined space suddenly where it will turn instantly into live wet steam which will fill the volume of the boat instantly and scald any life form to death is a truly frightening idea.

DON'T DO IT.

 

There is no way of achieving close temperature and over temperature control on a solid fuel boiler in a boat.

 

I know that it is sometimes difficult to arrange a heat soak by gravity but it is the ONLY save way. Really you need a dump for the maximum output of the boiler, the calorifier is the ideal one failing that enough radiator area to cope with sufficient thermosyphon flow will do.

 

Calorifier is a non starter if horizontal,  the only way is to arrange the gravity pipework flow high enough from the boiler  to enable the return to run uphill back to the boiler return, not easy. The head of flow by gravity is very small, pipework needs to be large bore and direct with absolute minimum resistance to achieve a good result, not easy to calculate accurately.

 

The radiators can have the flow pipe up under the gunnel, the returns at lower level back to the boiler, no thermostatic valves either. Raising them up from the floor by a foot or more will help achieve circulation. Main flow and return need to be at least 22mm, preferably 28mm if the runs are anything other than short and direct. Bends rather than elbows.

 

There needs to be a constant rise in the flow pipe and a constant fall in the return back to the boiler with no dips, which more or less rules out plastic pipe. Never a good idea with solid fuel boilers anyway. Vents on all high points, drain/s on lowest point/s. Expansion and feed tank on a high point.

 

If you want to send me a layout diagram of the boat I can try and design for you.

 

Sam

Ok good points about a pressurised system in a small space, luckily I do have a stainless Steel header tank that I’ve acquired so all good there.  Iam at work atm but ill draw up a diagram of the boat for u to look at later with my initial lay out ideas. Thanks again Sam 

Link to comment
Share on other sites

5 hours ago, Boater Sam said:

I consider a solid fuel burning boiler that relies on an electric pump for any circulation to be an unsafe and dangerous installation based on 40+ years experience of heating systems and codes of practice.

And I agree with you

Link to comment
Share on other sites

There are a few films of sealed system failures on the net.

One shows a cylinder going from the ground floor out through the roof at great speed whilst the steam generated blows all the windows and some walls out of a 2 story house. alarming.

 

This is why a certificate and training for installers is mandatory for installations of this ilk in domestic premises, unfortunately not boats. They never expected them to be installed I suppose.

 

I am not party to H&SE figures for such events but one would be bad enough, I have resisted doing any such works all the time I have been working on boats. Always managed to find a safe gravity solution with a little compromise.

 

Sam.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.