Hot Water

[benthom26]

Hi,

I have a Potterton Promax Combi HE Boiler and recently been experiencing problems with the hot water not being that hot, lukewarm at the best sometimes.
I have found that if I run the hot water tap much slower it tends to be much hoter.

Is this just due to cold weather outside? I have never experienced it this bad previously.... or could something have worn out and need replacing?

Thank you - hope someone can help.

Ben

 

[benthom26]

Just wanted to add that my central heating appears to be working fine.


Ben

 

[StudWall]

what happens if you turn the hot water on slowly, then when it gets hot, turn the tap up again, does it stay hot?

 

[benthom26]

Hi, sorry only just saw your response.

The water does appear to stay very hot if I do this!

What could be causing this?


Thank you

 

[StudWall]

Its basically the warm-up time of a combi.

If you turn the tap on then the boiler fires up and needs to heat the heat exchanger which in turn heats the water.

If you turn the tap on a little then the boiler will turn on full whack to heat the heat exchanger first, then as this raises the temperature of the water it can decrease its burn power to heat the water to the correct temperature.

This burn rate depends on the flow rate, which is how much you have your tap on.

if you turn the tap on further the boiler will increase its power to heat more water to the correct temperature.

When you turn the tap on fully straight off then it's possible that the boiler can't cope with the flow rate because the water is cooling down the heat exchanger too much for it to heat to the correct temperature.

Turning the tap on gently for a few seconds allows the boiler time to warm up the heat exchanger first.

Hope that makes sense

 

[benthom26]

Thank you for your advice.

Will give this a go.