geem
Well-Known Member
Just got some tables out. Assume 55degC difference between water in pipe and engine room. 15mm copper pipe. Heat loss is 45w/m run of pipe. Copper will be far better at losing heat than rubber
Calorifier hot water is too hot
- Thread starter Yeoman_24
- Start date
Just got some tables out. Assume 55degC difference between water in pipe and engine room. 15mm copper pipe. Heat loss is 45w/m run of pipe. Copper will be far better at losing heat than rubber
macd
Well-Known Member
That's fine if you want your shower water at the same temperature as the sink supply. People who wear Marigolds (to wash up, not shower
) often prefer the latter hotter than the former. In that case, a thermostatic shower mixer can be a better solution. (It also saves water wasted whilst fiddling to get your preferred temperature.) If you're lucky, the unit will be a direct swap.
RichardS
N/A
I appreciate that you seem to want to debate the minutiae of this but I'm afraid that I am not prepared to waste any more time on something which might not even be the OP's issue.
Richard
Tim Good
Well-Known Member
What's the ddisadvantgae of a calorifer getting too hot? My engine makes our hot water bloody hot but it never seems to have been a problem and the 20 year old plastic push fit connections seem to be holding up just fine.
macd
Well-Known Member
Semantically, "too hot" is nothing if it is not excessive. Practically, young children on board?
geem
Well-Known Member
Richard, I sorry that you think I am wasting your time. I am simply pointing out the risk of scolding. When somebody says there isnt a risk and they are factually wrong I think it needs correcting. It isnt just the OP that reads these posts.I appreciate that you seem to want to debate the minutiae of this but I'm afraid that I am not prepared to waste any more time on something which might not even be the OP's issue.
Richard
macd
Well-Known Member
Hoolie
Well-Known Member
How can young children get anywhere near the calorifier? On my boat it's buried at the bottom of the starboard cockpit locker.
All the way through this thread a mixer valve, ideally mounted on the calorifier, has been suggested by multiple posters, including me, that eliminates any risk of scalding (or even scolding!) at the hot water taps and shower.
RichardS
N/A
This is one of the strangest threads I've ever seen on PBO.
The OP seems to pop in and out of the thread but appears to simply not want to clarify exactly what the problem is.
Richard
The OP seems to pop in and out of the thread but appears to simply not want to clarify exactly what the problem is.
Richard
grumpy_o_g
Well-Known Member
This is one of the strangest threads I've ever seen on PBO.
The OP seems to pop in and out of the thread but appears to simply not want to clarify exactly what the problem is.
Richard
I like this kind of thread. It's like a good conversation in the pub when just enough beer has been consumed for everyone to stop understanding what everyone else is saying but not enough for anyone to realise that they don't understand any more. Equally good when viewed from inside the conservation or outside but for totally different reasons.
macd
Well-Known Member
If the universal default were that such a mixer were fitted at the calorifier, we wouldn't be having this conversation. It isn't, so the risk, and this thread, exists. I don't think anyone's suggesting a mixer valve wouldn't be a solution.
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Yeoman_24
Well-Known Member
I thought it was pretty clear. Basically, the hot water is ........... too hot!This is one of the strangest threads I've ever seen on PBO.
The OP seems to pop in and out of the thread but appears to simply not want to clarify exactly what the problem is.
Richard
My post at #16 thanks people for advice and outlines what I’m going to do but asks a specific additional question.
I don’t sit glued to the screen but read the flow of replies and opinions.
Personally I’m not worried if they are are too detailed for my needs or not. I’m just grateful people have read my thread and are posting if they feel their input may help ....... and the opinions flow!
I agree with grumpy_o_g’s observations at #30.
Chill ��
PCUK
Well-Known Member
Right Mr Yeoman. Just to summarise. Ignore the engine and the connections between the engine and calorifier. These have nothing to do with your problem. Equally the accumulator tank has nothing to do with it. It is the hot water coming from the calorifier to the taps that needs attention. As has been said numerous times already, you need to install an automatic thermostatic mixer valve that connects both the hot and cold feeds. One from the calorifier (hot water) and one from the water tank (cold water). This will then supply hot water to both the shower and the basin taps at the temperature you set it at. You can obtain one from any marine water system supplier such as ASAP, Zylem (AKA Cleghorn Waring). You can still manually adjust your shower temperature using the shower mixer in the shower compartment, so set the thermostatic valve slightly higher so as to avoid Legionella and to provide hotter water for washing up. Hope this clarifies things for you.
RichardS
N/A
Why will you not simply say "engine", "immersion" or "both"? One word will suffice. :encouragement:
Richard
PaulRainbow
Well-Known Member
The purpose of the thermostatic valve is to make sure that no matter how someone sets a tap or shower they cannot get scalded, no matter how the water was heated. Setting the immersion 'stat to a lower setting is not the answer, because the engine can still heat it to a temperature hot enough to scald.
Also, turning the immersion 'stat down means you have a tank full of warm water. Let's say you have a 22l tank, that gives you 22l of water for a shower. If the water in the tank was twice as hot as you needed for a shower and you had a thermostatic valve, this will mix the water after the tank but before the shower, effectively giving you 44l of shower temp' water.
Thermostatic vales are pretty standard on many calorifiers these days.
Also, turning the immersion 'stat down means you have a tank full of warm water. Let's say you have a 22l tank, that gives you 22l of water for a shower. If the water in the tank was twice as hot as you needed for a shower and you had a thermostatic valve, this will mix the water after the tank but before the shower, effectively giving you 44l of shower temp' water.
Thermostatic vales are pretty standard on many calorifiers these days.
lw395
Well-Known Member
Bear in mind that with some of these things, odd things can happen.
If the pump is switched off, the air space in the calorifer can cause the hot water to be pressurisd when the cold isn't. So the anti-scald valve cannot mix in cold water.
In some cases, people have reported getting hot water out of the cold tap.
Our hot water system behaved differently after we had a bit of spinnaker broach, I think putting the boat on its ear let some trapped air out of the calorifier or something, but the pump short-cycled after that until I replaced the accumlator which was full of water.
Having a pressure accumulator on the cold side and leaving the pump switched on may be best?
If the pump is switched off, the air space in the calorifer can cause the hot water to be pressurisd when the cold isn't. So the anti-scald valve cannot mix in cold water.
In some cases, people have reported getting hot water out of the cold tap.
Our hot water system behaved differently after we had a bit of spinnaker broach, I think putting the boat on its ear let some trapped air out of the calorifier or something, but the pump short-cycled after that until I replaced the accumlator which was full of water.
Having a pressure accumulator on the cold side and leaving the pump switched on may be best?
Yeoman_24
Well-Known Member
It does thank you.
RichardS
N/A
Maybe .... maybe not. It's clear that we'll never know.
Either way, well over 1000 people have enjoyed the conundrum so it's a good result. :encouragement:
Richard
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PaulRainbow
Well-Known Member
Maybe .... maybe not. It's clear that we'll never know.
Either way, well over 1000 people have enjoyed the conundrum so it's a good result. :encouragement:
Richard
Sorry Richard, but i don't think it matters how the water is being heated.
If it's the engine, you can't turn it down.
If it's the immersion heater, you can, but then you have a tank full of warm water, as i said above.
If a thermostatic valve is fitted it cures the problem, no matter the heat source and mixing very hot water with cold water gives you twice as much warm water.
RichardS
N/A
I don't disagree. I just said we'll never know whether the engine can get it hot enough to scald. I'm sure I'm not the only one of the 1000 viewees who believes that there is something odd going on here but, as I said, it's all part of the fun of the forum.
Richard