Calorifier problems

dgadee

dgadee

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I installed a 30l calorifier. I am having problems. I fitted a cockpit shower directly into the hot outlet from the calorifier (just 200mm from that outlet). This is very hot when shower tap turned on and then cools a bit, but could scald if not careful.

Setting the temperature for a non scalding cockpit shower means that hot water to the rest of the boat is far too cold.

What might you suggest I do?

Have emailed Surecal but email is bouncing.
 
I had the same issue with my internal shower then I fitted a thermostatic mixer valve that solved the problem.

I may also need to fit one to my outside shower some time in the future.
 
dgadee said:
I installed a 30l calorifier. I am having problems. I fitted a cockpit shower directly into the hot outlet from the calorifier (just 200mm from that outlet). This is very hot when shower tap turned on and then cools a bit, but could scald if not careful.

Setting the temperature for a non scalding cockpit shower means that hot water to the rest of the boat is far too cold.

What might you suggest I do?

Have emailed Surecal but email is bouncing.
Click to expand...
When you say "setting the temperature" do you mean setting the temperature on the thermostatic mixing valve on the calorifier?

Richard
 
You still need a cold water feed to the shower, with a mixer valve, thermostatic or otherwise, adjustable from the shower position; this mixer is not the same as the calorifier thermostatic mixer valve that you already seem to have. The setting on the calorifier mixer valve should be such that hot water to the shower, sinks and washbasins is not dangerously hot but nevertheless is too hot for washing and washing-up without the addition of cold water.
 
PeterBoater said:
You still need a cold water feed to the shower, with a mixer valve, thermostatic or otherwise, adjustable from the shower position; this mixer is not the same as the calorifier thermostatic mixer valve that you already seem to have. The setting on the calorifier mixer valve should be such that hot water to the shower, sinks and washbasins is not dangerously hot but nevertheless is too hot for washing and washing-up without the addition of cold water.
Click to expand...

My mixer valve is set to a suitable temperature for washing, showering and washing up. My taps are all mixer taps, but if i eed hot water i just turn the hot tap on. Doing it your way does no harm, of course, but it isn't a must do way.
 
Perhaps I should have made my post above clearer. I am about to fit a mixer valve that reduces the temperature of the cockpit shower to a lower level than the general hot water. It does not involve an extra cold water connection to the shower head and is adjusted adjacent to the calorifier to a fixed temperature to be agreed by the management!
 
PaulRainbow said:
My mixer valve is set to a suitable temperature for washing, showering and washing up. My taps are all mixer taps, but if i eed hot water i just turn the hot tap on. Doing it your way does no harm, of course, but it isn't a must do way.
Click to expand...
Interesting but I prefer very different temperatures for each, so three mixing taps.
 
At home, kitchen hot tap runs up to about 60degC. Shower is 39degC according to the dial.
Calorifer will get up to 90+degC if you thrash the engine. That's unwise on a galley tap, bloody dangerous for a shower.

There is a trap that thermostatic mixers may work badly if the hot pressure is higher than the cold, and that can happen due to the hot expanding. In the limit, the hot water can force itself into the cold circuit with strange and possibly terrible results.
You should make sure it's all safe in all circumstances IMHO. Like when there is no cold pressure 'cos the pump is off.

Mind how you go!
 
A decent thermostatic shower mixing valve will have non return valves incorporated in both hot and cold supplies to prevent this.
If the budget will allow could I recommend Grohe as an excellent safe mixer? Avoid the cheap stuff, they have plastic parts that will let you down.
 
Seems like a few people here are confusing mixer taps/shower mixers with thermostatic mixer valves. The Surecal calorifiers have a thermostatic mixer valve at the hot outlet of the calorifier, this means that the temperature of the hot water reaching the hot tap can be controlled. The water in the tank could be 85c, but it could be mixed at the outlet to arrive at the hot tap at 45c (or whatever temp you want). That's just at the hot tap, further mixing can be done with the mixer taps at the sink/wash basin/shower.
 
TernVI said:
At home, kitchen hot tap runs up to about 60degC. Shower is 39degC according to the dial.
Calorifer will get up to 90+degC if you thrash the engine. That's unwise on a galley tap, bloody dangerous for a shower.
Click to expand...

The OP has a thermostatic mixer valve at the calorifier, so if he set that to, say, 45c the water coming out of the hot tap would be 45c, no matter how hot it is in the tank.

There is a trap that thermostatic mixers may work badly if the hot pressure is higher than the cold, and that can happen due to the hot expanding. In the limit, the hot water can force itself into the cold circuit with strange and possibly terrible results.
Click to expand...

How does the hot pressure get higher than the cold, it's all pumped by a single pump ? The pressure in the calorifier should not increase with temperature, as an expansion vessel should be fitted, the OPs calorifier warranty is void without one. Hot water cannot force itself into the cold circuit in a proper installation, in the OPs case, he should have fitted an expansion vessel, for one thing, for another, his calorifier has a non return valve fitted to the cold inlet.

You should make sure it's all safe in all circumstances IMHO. Like when there is no cold pressure 'cos the pump is off.
Click to expand...

If the pump is turned off there will be no water at all at the taps, it's a pressurised system, working from a single pump.[/quote][/QUOTE]
 
OP here. I have no expansion tank. Might that be the problem? Or is the cockpit shower tap connected too close to the tank?

We only want one temperature for hot water throughout the boat. Currently in Bay of Naples, so hot enough around us.
 
dgadee said:
OP here. I have no expansion tank. Might that be the problem? Or is the cockpit shower tap connected too close to the tank?

We only want one temperature for hot water throughout the boat. Currently in Bay of Naples, so hot enough around us.
Click to expand...
That’s exactly the reason I prefer very different temperatures around the boat. I always want washing up water to be hot but often want tepid showers.

I understand Paul Rainbows post about having a thermostatic valve and mixer taps as needed now, but still not sure of the benefit compared to mixer taps alone.
 
PeterBoater said:
You still need a cold water feed to the shower, with a mixer valve, thermostatic or otherwise, adjustable from the shower position; this mixer is not the same as the calorifier thermostatic mixer valve that you already seem to have. The setting on the calorifier mixer valve should be such that hot water to the shower, sinks and washbasins is not dangerously hot but nevertheless is too hot for washing and washing-up without the addition of cold water.
Click to expand...
I was just about to write the same reply. I would add that the purpose of the dedicated calorifier mixer valve is to ensure that water from the calorifier that can reach circa 85degC does not burn somebody. It allows a small calorifier to store plenty of energy in the hot water. You would normall set this thermostatic mixer valve to a hot temperature so as not to scold but generally for showering you would have a dedicated thermostatic mixer at the point of us
 
dgadee said:
OP here. I have no expansion tank. Might that be the problem? .
Click to expand...
The expansion tank will not affect the temperature. Some people will tell you an expansion tank is essential. My calorifier has lasted 20 years without one. Any excess pressure from heat expansion is relieved by the pressure relief valve.

It is up to you where thermostatic mixer valves are installed (if at all) dependent on what water temperatures you want around the boat and/or if you have mixer taps at the outlets.

If you fit a thermostatic mixer valve in the hose that feeds the deck shower you will need to install a separate cold supply to that valve so that valve can mix the hot and cold, to the temperature you set, so you have a nice temperature for the deck shower.


www.solocoastalsailing.co.uk
 
Last edited:
dgadee said:
OP here. I have no expansion tank. Might that be the problem? Or is the cockpit shower tap connected too close to the tank?

We only want one temperature for hot water throughout the boat. Currently in Bay of Naples, so hot enough around us.
Click to expand...
Ah .... if you're in the Med I do wonder why your deck shower is plumbed into the hot water side at all?

Our deck shower is not a mixer fitting but plumbed into the "cold" side although it is never cold and has never caused even a moment's discomfort.

Richard
 
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