CH Heating problem....help!.

[cherryturbox]

I have a gloworm boiler 1987 fitted. the radiators have individual TRV valves, there is no room thermostat, there is a Danfoss timer that switches the hot water or CH independently. The problem is the CH wont come on unless the hot water is switched on and the hot water tank thermostat is turned up above the temperature of the water in the hot water tank. The system gets us through the winter but the CH wont work independently of the hot water system. I have changed the Danfoss timer unit, the boiler thermostat, hot water tank thermostat also the three port valve is fairly new as well. The hot water heating works ok during the summer when CH heating is not required and the radiators do not get hot.

Any ideas any body?.

kevin.

 

[dcawkwell]

I have a gloworm boiler 1987 fitted. the radiators have individual TRV valves, there is no room thermostat, there is a Danfoss timer that switches the hot water or CH independently. The problem is the CH wont come on unless the hot water is switched on and the hot water tank thermostat is turned up above the temperature of the water in the hot water tank. The system gets us through the winter but the CH wont work independently of the hot water system. I have changed the Danfoss timer unit, the boiler thermostat, hot water tank thermostat also the three port valve is fairly new as well.

Any ideas any body?.

kevin.

3 port valve is not switch the boiler on when CH is selected is usual most likely. Easy enough to check with a multimeter. Stop wasting money changing parts. It is easy to verify if a part if faulty and find the cause.

 

[MANDATE]

Looks like your valve goes to mid position so motor Ok.
So theres a couple of things to consider.
Either the valve is not receiving power on the 'grey' wire so the valve does not move to CH position and cannot trigger the micro switch to light boiler.
Or it does move and the micro switch is faulty

 

[cherryturbox]

Looks like your valve goes to mid position so motor Ok.
So theres a couple of things to consider.
Either the valve is not receiving power on the 'grey' wire so the valve does not move to CH position and cannot trigger the micro switch to light boiler.
Or it does move and the micro switch is faulty

Hi, I have checked voltage on the grey wire, with the danfoss timer switched on for the CH and 240v to neutral measured. what colour is the output wire from the micro switch? perhaps check voltage here. valve moves to mid position ok.

 

[MANDATE]

Looks like your valve goes to mid position so motor Ok.
So theres a couple of things to consider.
Either the valve is not receiving power on the 'grey' wire so the valve does not move to CH position and cannot trigger the micro switch to light boiler.
Or it does move and the micro switch is faulty

Hi, I have checked voltage on the grey wire, with the danfoss timer switched on for the CH and 240v to neutral measured. what colour is the output wire from the micro switch? perhaps check voltage here. valve moves to mid position ok.

With 240v on the grey valve should move to CH position. If it does not! then contacts in micro switch 1 could be stopping it.
IF it does move to CH position and boiler does not light then contacts in micro switch 2 are stopping power out of the valves 'orange'wire.
Best solution is to replace actuator head

 

[cherryturbox]

Looks like your valve goes to mid position so motor Ok.
So theres a couple of things to consider.
Either the valve is not receiving power on the 'grey' wire so the valve does not move to CH position and cannot trigger the micro switch to light boiler.
Or it does move and the micro switch is faulty

Hi, I have checked voltage on the grey wire, with the danfoss timer switched on for the CH and 240v to neutral measured. what colour is the output wire from the micro switch? perhaps check voltage here. valve moves to mid position ok.

With 240v on the grey valve should move to CH position. If it does not! then contacts in micro switch 1 could be stopping it.
IF it does move to CH position and boiler does not light then contacts in micro switch 2 are stopping power out of the valves 'orange'wire.
Best solution is to replace actuator head

Hi, I have checked the incoming white wire for CH demand and it is live at 240v when CH is switched on at the Danfoss, however no voltage on the orange, so yes looks like a switch problem, I believe the valve is moving correctly, so will get a new valve assembly, but I think I can change it without removing the pressure pipework parts as there are only two screws on the mounting plate.

kevin.

 

[cherryturbox]

I have a gloworm boiler 1987 fitted. the radiators have individual TRV valves, there is no room thermostat, there is a Danfoss timer that switches the hot water or CH independently. The problem is the CH wont come on unless the hot water is switched on and the hot water tank thermostat is turned up above the temperature of the water in the hot water tank. The system gets us through the winter but the CH wont work independently of the hot water system. I have changed the Danfoss timer unit, the boiler thermostat, hot water tank thermostat also the three port valve is fairly new as well.

Any ideas any body?.

kevin.

3 port valve is not switch the boiler on when CH is selected is usual most likely. Easy enough to check with a multimeter. Stop wasting money changing parts. It is easy to verify if a part if faulty and find the cause.

no harm in changing 25 year old thermostats!.