Central Heating Hot water is so hot it scalds!!

[MartH]

I have an IMI Range Power Max 135 Boiler which runs both Hot Water feed and Central Heating.

Recently the boiler has started to ‘bang’ &’knock’ very loudly with a noticeable increase in both radiator and water temperature (to the point were it scalds if you put your hand under it!)

British Gas say that the knocking is due to scale build up and are advising a power flush to fix the problem but as of yet made no comment about the temperature of the water…

My question is this: after measuring the water temp I have found it to be 70Deg C is this to hot for hot water in a domestic system and could this be the cause of the mysterious banging?

Thx

Mart

 

[ollski]

yes it is too hot, it is preset at the blending valve to be 60 deg...would guess that to be faulty. The central heating water should be 70 deg, if that is too hot suspect a thermostat. The temperature of the cylinder is the temp of the heating water as the powermax is a thermal store cylinder and stores central heating water. The banging and crashing is most likely to be a scaled dhw heat exchanger yes.... a powerflush may help if you also have sludged up water running through it, but it won't remove any scale.

 

[MartH]

Hi Ollski

Thx for the reply!

Reading between the lines with what you have said the powerflush will offer no real benefit for the crashing and banging as the scale will still be caked on to the heat exchanger - the only real thing it will do is flush out the sludge from the system...

In regards to the scale and the knocking and banging I cannot really do a lot about it - what long term effects will this cause to the heating system?

M