Hot water goes cold

[price1981]

1) Boiler make / model (gas or oil)
Glow worm 30ci (gas)

2) What is / is not happening.
Hot water is inconsistent. Heating works fine but when hot water taps are switched on, sometimes only cold comes through, other times it goes hot for a short while before going cold, and sometimes it works normally.

3) Has ANYTHING else been done or changed recently.
No

4) When did the problem start?
A week ago

5) When does it happen? eg, heating coming on or going off.
This happens whether the heating is on or off.

Will be calling a Corgi registered plumber to take a look but wondered whether this is likely to be an easy fix? Also, how much it could potentially cost.

Thanks

 

[Dan Robinson]

Could be a clogged plate heat exchanger or duff diverter valve.

With the heating off AND cold, run the hot water, does the heating flow pipe get warm?

If so its the diverter..

If not then look to heat exchanger or possibly a temperature sensor.

 

[price1981]

thanks Dan, will give that a try.