no hot water but central heating working

[adam33]

Hi, wonder if you can help, developed problems with heating up the hot water but reading this forum I can confirm the following:
1. the central heating / radiators works ok
2. when hot water is set by the controller/timer the motorised valve seems to work.
3. I have replaced the cylinder thermostat.
4. When motorised valve is set to manual and heating is set the water also heats up
5. water filling up ok
6. checked for any air locks (via cyclinder tank bleed valve)

Can anybody suggest anything else??

 

[Agile]

You need to determine if the motor valve is moving to the correct position when only hot water is selected.

If not then a thermostat/timeclock/electrical problem.

If the motor valve IS moving then it would seem the switch in the valve is not being actuated when the valve has reached the correct position.

Tony

 

[Gasguru]

I assume your system has two two port zone valves.

Perhaps the hot water valve appears to work but the motor is not opening the valve fully and then switching on the boiler.