Calorifier hot water is too hot

Yeoman_24

Yeoman_24

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I believe that I can somehow fit a thermostatic valve to permanently blend my calorifier very hot water with the cold to make temperature safer. Any help greatfully appreciated.
PS, also have an accumulator (?) too.
 
Main safety requirements are for safe showering with my Whale mixer tap with extending tap head on a hose.
I have flexible pipes rather than 15mm brass pipe. I also have an accumulator, so, help and actual advice would be appreciated please. Thanks.
 
Last edited:
XDC said:
Lost me.

I have what you have, a MIXER tap with an extending tap head on a hose.

Flexible pipes and an accumulator which is irrelevant to your question. It merely evens out the flow.

I use the mixer tap to mix the hot and cold to a safe temperature
Click to expand...

My understanding in accumulator regulates flow to reduce pump kicking in. But if halfway through a shower, the pump does kick in, surely that could cause a scald?
 
Yeoman_24 said:
Main safety requirements are for safe showering with my Whale mixer tap with extending tap head on a hose.
I have flexible pipes rather than 15mm brass pipe. I also have an accumulator, so, help and actual advice would be appreciated please. Thanks.
Click to expand...

Just buy a valve and connect it to your pipework. How about a Whale one, with threaded ports :

https://www.whalepumps.com/marine/s...accessories-spares/ThermostaticMixerValve.pdf

Fit it with hose tails to suit your pipes and it's job done.
 
colind3782 said:
If it's the immersion heater that's making the water hot on shore power, just turn the thermostat down?
Click to expand...

There should be a tiny screw in the end of the thermostat that can be rotated to adjust temperature. One would need a small electric screw driver. My one has an arrow on the plastic casing indicating direction to turn but I need a magnifying glass & torch to see it & the hole where the screw is
 
Fit a mixer valve as Paul Rainbow suggests and set it at a safe 50 Deg. Turn your calorifier up to 80 Deg. Then when it's mixed with cold at 20 Deg down to 50 Deg you will get twice as much hot water from your taps as there is water in the calorifier.
 
Last edited:
Hoolie said:
Fit a mixer valve as Paul Rainbow suggests and set it at a safe 50 Deg. Turn your calorifier up to 80 Deg. Then when it's mixed with cold at 20 Deg down to 50 Deg you will get twice as much hot water from your taps as there is water in the calorifier.
Click to expand...

That is why I have one of these on my to do list. Cheap one here:

https://www.asap-supplies.com/domestic-water-supply/calorifiers-water-heaters-fittings/calorifier-valves-fittings/hotpot-thermostatic-mixing-valve-520955
 
Hoolie said:
Fit a mixer valve as Paul Rainbow suggests and set it at a safe 50 Deg. Turn your calorifier up to 80 Deg. Then when it's mixed with cold at 20 Deg down to 50 Deg you will get twice as much hot water from your taps as there is water in the calorifier.
Click to expand...

Is 50C hot enough to control Legionella ?

There are two temperatures to consider. The minimum WHO recommendation to control Legionella and the maximum H&S recommendation to avoid scalding.
 
RichardS said:
That was my reaction as I was thinking that presumably the engine calorifier is not producing that level of temperature?

However, I'm still not clear whether we are talking about the immersion heater or engine heating or both. :confused:

Richard
Click to expand...

Why do you think the engine cant produce that kind of temperature? My engine when up to temperature sits at 90degC on the gauge. The calorifier is well insulated. The flow from the engine has no thermostatic control. Given enough time, the water in the calorifier will start to approach the engine temperature.

Turning down the settings on the immersion heater won't work and with a high engine temperature can cause another problem. The immersion heater may have a high limit cut out that gets tripped every time the engine water forces the immersion heater over its set safety limit.
We have a high quality domestic shower valve that easily deals with different pressures from hot and cold supply and somebody turning the cold tap on whilst you are in the shower. When somebody points out a cheap thermostatic valve it worries me. You need to fit the best because if it goes wrong the burns could be horrific.
 
geem said:
Why do you think the engine cant produce that kind of temperature? My engine when up to temperature sits at 90degC on the gauge. The calorifier is well insulated. The flow from the engine has no thermostatic control. Given enough time, the water in the calorifier will start to approach the engine temperature.

Turning down the settings on the immersion heater won't work and with a high engine temperature can cause another problem. The immersion heater may have a high limit cut out that gets tripped every time the engine water forces the immersion heater over its set safety limit.
We have a high quality domestic shower valve that easily deals with different pressures from hot and cold supply and somebody turning the cold tap on whilst you are in the shower. When somebody points out a cheap thermostatic valve it worries me. You need to fit the best because if it goes wrong the burns could be horrific.
Click to expand...

I'm still not sure whether we are talking about the immersion heater, the engine calorifier or both and until we have that information then we are all just guessing. :)

However, if it is an immersion heater, then why won't turning down the thermostat work? :confused:

The engine certainly can produce high temperatures but there is usually only a relatively small bore, non-insulated, hose connecting the engine coolant system to the calorifier, and, depending upon how long that hose is, plus the other losses in the calorifier and the hoses running from the calorifier to the shower outlet, I am suggesting that the output from the shower head is unlikely to reach engine temperature unless one is running the engine for a long time and ambient temperatures are elevated. :)

Richard
 
I'm still not sure whether we are talking about the immersion heater, the engine calorifier or both and until we have that information then we are all just guessing. :)
Click to expand...
Not an issue if the OP fits a mixer valve - standard practice on boat calorifiers and domestic HW systems alike
 
Thanks everyone for advice, links and ideas. I wasn’t aware that there should be a thermostat on the calorifier so that’s my first point af call to find that followed by fitting the thermostatic valve.
Does it matter if valve is next to the calorifier or is it ok to be at the other end of the boat where the heads are and it will be an easier job to install?
 
Yeoman_24 said:
Thanks everyone for advice, links and ideas. I wasn’t aware that there should be a thermostat on the calorifier so that’s my first point af call to find that followed by fitting the thermostatic valve.
Does it matter if valve is next to the calorifier or is it ok to be at the other end of the boat where the heads are and it will be an easier job to install?
Click to expand...

Its an electric immersion heater that requires a thermostat and which is normally built into the heater.

The thermostatic mixer valve is normally connected directly to the calorifier and simply provides a temperature controlled hot water supply.

 
Yeoman_24 said:
Thanks everyone for advice, links and ideas. I wasn’t aware that there should be a thermostat on the calorifier so that’s my first point af call to find that followed by fitting the thermostatic valve.
Does it matter if valve is next to the calorifier or is it ok to be at the other end of the boat where the heads are and it will be an easier job to install?
Click to expand...

I'm still not clear I'm afraid. Are you referring to how hot the water gets when it has been heated up by shorepower electricity?

Richard
 
RichardS said:
The engine certainly can produce high temperatures but there is usually only a relatively small bore, non-insulated, hose connecting the engine coolant system to the calorifier, and, depending upon how long that hose is, plus the other losses in the calorifier and the hoses running from the calorifier to the shower outlet, I am suggesting that the output from the shower head is unlikely to reach engine temperature unless one is running the engine for a long time and ambient temperatures are elevated. :)

Richard
Click to expand...
since the risks of scolding is there, (you run the engine for a day to reach your destination) then you need some thermostatic control of the water coming out of the calorifier. Even with uninsulated small bore pipes (mine are 15mm inside diameter) the heatloss from the pipes and calorifier has to be greater than the Watts of energy going in to the calorifier or the temperature of the stored water in the calorifier will elevate. Rubber hose is a surprisingly good insulator. The heat loss from plain unfinned pipes is only a few watts per meter. Believe me, if I run our hot tap to the galley for a minute the water temperature is scolding. We have it like this on purpose as it means a relatively small calorifier can store a lot of energy. You have to be very aware of the risks. The risk isn't worth taking with a shower so top quality thermostatic valves are essential
 
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