Cylinder thermostat stops CH coming on

[tdlynn]

Hi There,

Quick question.

We have a pretty standard system at home with a boiler downstairs, cylinder in airing cupboard which provides hot water for CH and HW.

However, when the water in the cylinder has heated up sufficiently to cause the thermostat to kick in, it stops the CH pump and therefore stops the house from being heated.

If I turn the cylinder thermostat up, the pump kicks in and the boiler turns on and starts heating the radiators.

What is the problem?

My guess is the three way port, although this was only changed a year ago as it was fault before.

Any ideas?

Cheers

Tom

 

[Puddle]

Could be the micro switch on the cylinder thermostat sticking and not sending power to moitorised valve,turning to heating only when hot water satisfied

 

[aggis]

Has the 3 way valve been fitted the right way around ? A to heating B to cylinder

 

[tdlynn]

Hi Guys,

Thanks for your replies. I went back to have another look at it and followed another post on here about a testing procedure to work out what was going wrong with the three way valve.

This didn't seem to show me much apart from the actual valve was working fine.

Then I noticed that one of microswitches was slightly bent back and when the actuator was being moved round, it would activate one microswitch but not the other one. When I'd press the second microswitch with a screwdriver, the CH would start. So I bent the switch out a bit so that they would both be activated and it seems to have solved the problem.

Thanks for the feedback.. hopefully this may help someone else with the same problem.

All the best

Tom