dgadee
Well-Known Member
Crew demands it warm.
I am beginning to think shower outlet too close to tank output.
Calorifier problems
- Thread starter dgadee
- Start date
Crew demands it warm.
I am beginning to think shower outlet too close to tank output.
RichardS
N/A
Within reason, no matter how far away from the calorifier output you have it, it will run up to full temperature after max 30 seconds or similar. It would be OK for very short showers but as that initial 30 seconds is, more or less, the same temperature as the cold water tank, you might as well just plumb it into the cold system if 30 seconds is all that's required.
If your crew shower for long enough to wait for the warm water to come through, then a few seconds after it gets warm, it will be up to full heat and too hot.
Richard
dgadee
Well-Known Member
Other way about. Starts scalding then goes to set temperature.
RichardS
N/A
Ah .... I see. It sounds as if there is a delay before the mixer starts mixing and that it lets through fully hot water for a few seconds until it starts to mix in the cold water,
Provided that that temperature setting is hot enough for all the other outlets, then you could well be right that moving the shower connection further away from the thermo mixer will probably work. Even easier might be to just try a longer hose to the shower head, even if some of it is coiled up below decks and not actually used.
Richard
TernVI
Well-Known Member
That could be because the HW starts at a higher pressure due to expansion, so although the mixer valve opens thermostatically, no cold water is added until the pressure equalises.
The expansion in question is likely air space in the calorifier?
Graham376
Well-Known Member
Problem is, many boats with older calorifiers such as ours don't have an expansion tank or thermostat on engine heated hot supply so it's around 80 degrees. We just have mixer taps, not thermostatic ones and it's easy enough to balance the temperature at all, two of which in the heads have shower heads. We only have a pressure vessel on the cold from the pump to stop it cycling. In theory it should be updated but, if it ain't broke.......
PaulRainbow
Well-Known Member
Surecal warranty is void without the expansion tank, 5 litres in your case. Surecal tanks are fitted with non return valves at the cold inlet, so the water in the tank cannot expand into the cold system, which it often did with systems not fitted with a non return valve. Post #25 could be correct.
PaulRainbow
Well-Known Member
Problem is, many boats with older calorifiers such as ours don't have an expansion tank or thermostat on engine heated hot supply so it's around 80 degrees. We just have mixer taps, not thermostatic ones and it's easy enough to balance the temperature at all, two of which in the heads have shower heads. We only have a pressure vessel on the cold from the pump to stop it cycling. In theory it should be updated but, if it ain't broke.......
I agree there's no need to change anything if it's working OK. The thermostatic valve has been added to calorifiers to stop that 80 degree water reaching the taps and scalding someone. I keep mine set to shower temp', and don't add further cold water at the taps, but i completely understand those that have it set higher and further regulate temp' at the mixer taps. Earlier systems got away with not having expansion tanks as they generally didn't have non return valves in the cold inlet.
ASAP supplies still sell calorifiers with no non return valve and these can be fitted without expansion tanks, the "problem" with this arrangement is that hot water expands into the cold system and when you turn the cold tap on some warm water can come out of it.
Hoolie
Well-Known Member
Our previous calorifier (with a non-return valve) was fitted without an expansion tank. Every time it heated up the pressure release valve wept a few ccs of water but the installer had omitted to connect it to an existing hose leading into the main bilge. Result was a continual trickle of water from the aft of the boat into the bilge via goodness knows where, making everywhere under the floor wet and the boat generally too damp to keep black mold at bay.
Graham376
Well-Known Member
We do in fact have a non return valve but without expansion vessel, it relies on the prv burping if pressure too high. Will do something about it one day - well, maybe
dgadee
Well-Known Member
I have one at home - took it off when I had pump problems. Unfortunately I am far from home. Bit I think you have explained my problem.