heating water

[colin loach]

Hi all, is there any reason I can’t connect my calorifier in line with my rinnia water heater so if I am using the water in the calorifier I can turn off the rinnia heater. I can’t find any information on bss web site, Colin

[bag 'o' bones]

Hi all, is there any reason I can’t connect my calorifier in line with my rinnia water heater so if I am using the water in the calorifier I can turn off the rinnia heater. I can’t find any information on bss web site, Colin

 

I assume you mean directing water straight from the calorifer through the heater to increase the temperature? Bit risky if the water coming from the hot water tank is already hot, you could get scolded as far as I am aware the majority of tankless heaters output temperatures are dependent on the original inlet temperature and don't sport a theromostat to prevent this happening (although I could be wrong). If the heater can control the final temeperature then I don't see why they can't be fitted in line and would certainly be away of saving on gas.

[Robbo]

I assume you mean directing water straight from the calorifer through the heater to increase the temperature? Bit risky if the water coming from the hot water tank is already hot, you could get scolded as far as I am aware the majority of tankless heaters output temperatures are dependent on the original inlet temperature and don't sport a theromostat to prevent this happening (although I could be wrong). If the heater can control the final temeperature then I don't see why they can't be fitted in line and would certainly be away of saving on gas.

 

You could fit a thermostatic mixer after the heater though!

[springy]

You could fit a thermostatic mixer after the heater though!

 

No good if the incoming water is hot enough such that the "tankless heater" is

able to boil it !

 

I've not seen any with any sort of thermostatic control on the outlet, usually

just a two or three position heat setting and a flow control valve allowing hotter

or cooler water.

 

AFAIK the fitting instructions for most of this type of heater require that it is

fed from a "cold" supply, and BSS would surely expect them to be installed

in accordance with the manufacturers instructions (even if there is some

leeway on flue length).

 

springy

[colin loach]

the problem is I mainly stay at the marina and have no mains electric so the only way to have hot water is through the wall heater. but when cruising the engine will hot up the water which will save gas, so is there away I can incorporate both and still pass the bss. colin.

[alan_fincher]

the problem is I mainly stay at the marina and have no mains electric so the only way to have hot water is through the wall heater. but when cruising the engine will hot up the water which will save gas, so is there away I can incorporate both and still pass the bss. colin.

Yes,

 

You can have hot water heated by the engine in a calorifier, as well as a Rinnai/Morco/Paloma type heater - ideal arrangement, in my view.

 

In my view it would not be safe though to plumb things such that the instantaneous heater is supplied by (potentially) hot water from the calorifier. The instructions on the heaters are quite explicit you must only feed with cold, and as they are capable of adding 50 degrees to temperature at a lower flow rate, there is a very good chance of producing boiling water and steam out your hot taps.

 

The trick is to have a big 2 way tap, (an "L port" valve, that simply selects which hot water source to use. Turned one way the water comes from the calorifier, and the output from the heater is blocked off. Turned the other way, the reverse happens.

 

We have this, and it works just great.

 

The L port valves can be hard to source, (but anybody who deals with Aqufax should be able to order you one in). You can just use two "on off" stopcocks, one in the feed from each, but your rule then must be that you are always closing one, whilst opening the other. The 'L port' valve is more idiot proof, so, in my view, worth doing.

[koukouvagia]

the problem is I mainly stay at the marina and have no mains electric so the only way to have hot water is through the wall heater. but when cruising the engine will hot up the water which will save gas, so is there away I can incorporate both and still pass the bss. colin.

 

You could make a simple plumbing alteration and incorporate of an L port valve. This will allow inlet to the calorifier to come from either the engine OR the heater – but not both.

 

 

Edited to say:

Beaten to it by Alan. You can get the L port valves from Acorn Engineering online chandlery

Edited January 27, 2010 by koukouvagia

[colin loach]

Thanks to all, what would I do without this forum. the three way valve solves all the problems and should satisfy the bss. it will take a day to alter the pipe work because I have to dismantle some of the kitchen , but after that its free hot water. so thanks again.Colin.

[Guest]

Yes,

 

You can have hot water heated by the engine in a calorifier, as well as a Rinnai/Morco/Paloma type heater - ideal arrangement, in my view.

 

In my view it would not be safe though to plumb things such that the instantaneous heater is supplied by (potentially) hot water from the calorifier. The instructions on the heaters are quite explicit you must only feed with cold, and as they are capable of adding 50 degrees to temperature at a lower flow rate, there is a very good chance of producing boiling water and steam out your hot taps.

 

The trick is to have a big 2 way tap, (an "L port" valve, that simply selects which hot water source to use. Turned one way the water comes from the calorifier, and the output from the heater is blocked off. Turned the other way, the reverse happens.

 

We have this, and it works just great.

 

The L port valves can be hard to source, (but anybody who deals with Aqufax should be able to order you one in). You can just use two "on off" stopcocks, one in the feed from each, but your rule then must be that you are always closing one, whilst opening the other. The 'L port' valve is more idiot proof, so, in my view, worth doing.

 

Which relaying this back to our other discussion/thread ref hire boat water heating - means the Ashby boat could have one of these valves or will that only work with an instantaneous heater and engine calorifier???

Edited January 27, 2010 by MJG

[springy]

<snip>

This will allow inlet to the calorifier to come from either the engine OR the heater – but not both.

 

I think you need to arrange the L port such that one side is fed from the Calorifier, the other

is fed from the tankless heater, and the outlet goes to the hot taps.

 

springy

[alan_fincher]

I think you need to arrange the L port such that one side is fed from the Calorifier, the other

is fed from the tankless heater, and the outlet goes to the hot taps.

 

springy

Yes,

 

You are correct.

 

I failed to clock Jim's response, but I don't think it is correct in the instantaneous water heater case - it's more like he is trying to make either the engine or a central heating boiler work into a calorifier with just a single coil, (possibly ?).

 

The calorifier will have an outlet for hot water, feeding hot taps.

 

The Morco will also have a hot water outlet.

 

You need to connect each of those outlets to the two selectable ports on the valve. The common port is then connected to hot taps.

 

With the valve set one way, water is drawn from the calorifier, with it set the other, then iot comes through the Morco.

 

For whichever source is not being used, the port in the valve is blocked off - that's exactly the same as it is when it's connected to the taps, but none of them are open. Both bits continue to work just like they would if they were the only hot water source present.

 

Obviously you need your cold (pumped) supply to be tee-ed so it feeds both a calorifier input, and a Morco input. Personally we also have ball valves in each, allowing either part to be shut off and drainedof water in freezing conditions, if we wish. Those valves, however, are not needed as part of the normal selection between sources.

 

Easy peasey!

 

 

Which relaying this back to our other discussion/thread ref hire boat water heating - means the Ashby boat could have one of these valves or will that only work with an instantaneous heater and engine calorifier???

No,

 

The L-port valve solution is only appropriate to the instantaneous (Morco) type heater, where water goes straight from heater to taps, and is never stored hot.

 

If you use a central heating boiler, then you use a second indirect circuit ("coil") in the calorifier. (The boiler heats the calorifier, and the resulting domestic hot water is not usually used "instantaneously").

 

It's perfectly possible to have both engine and boiler simultaneously heating calorifier water.

 

If a hire boat with oil or gas cental heating is not heating the calorifier then either....

 

1) The builder has decided not to provide the facility.

 

or

 

2) it is there, but has been disabled, either by valves or the way the boiler and pump are (or are not!) wired up, (or both!).

 

Inspection would easily show whether the plumbing to a second coil is there or not - I can't guess though.

[Guest]

<snip>

 

No,

 

<snip>

 

Thanks Alan,

[colin loach]

I can see that both ways would work, either putting the valve in the cold water supply or hot water outlet. but i think i will need to fit two one way valves in either case.

[blackrose]

I can see that both ways would work, either putting the valve in the cold water supply or hot water outlet. but i think i will need to fit two one way valves in either case.

 

I have a calorifier and a valiant instant gas water heater and plumbed them in the way Alan has described.

 

The system works very well. The only non-return valve is the standard one many people have just upstream of the calorifier to prevent expanding hot water backing up the cold feed pipe.

Edited January 28, 2010 by blackrose

[colin loach]

It will work easer for me to alter the pipe work if I follow Alans instruction which is good news. So thanks again for all your help. Colin