It appears my heating system is throwing a wobbly; I have a system boiler set-up (Ideal Standard ... I think, can check), hot water works fine but the heating is problematic.
When I adjusting the thermostat (Drayton RTS8, running on 24vdc) to kick the heating in to life results in relay chatter (he relay in in a separate box so easy to access and is the same as this one: IMO RS2PN 12DC IMO DPCO 10A 12DC RELAY | Kempston Controls - https://www.kempstoncontrols.co.uk/RS2PN-12DC/IMO/sku/428124). I'm no engineer but I'm guessing the thermostat throws the relay (assuming the usual timer / control panel heating is in the switched on position) which kicks a control board into supplying the boiler and valve serving the radiator circuit with a "go for it" ... and voila...heat. Something is getting in the way of that!
I've thrown a multi-meter across the thermostat (2-wire install) and its showing around 24Vdc when "not on" which drops to around 1.5-2Vdc when the temperature is turned up, at which point the relay goes nuts. I don't know if the second voltage is around the right level.
As a workaround I can flick the relay into test mode at which point the valve serving the radiators opens; thought this at least serves as a check the relay hasn't completely failed (although the chattering probably rules out a complete failure). Current workaround to obtain heat is to switch on the hot water and manually open the heating value but that only works as long as the cylinder thermostat doesn't feedback to shut it off when the water is at temperature.
Also to note is that the relay chatter is present once it the thermostat is turned up until it "clicks on" even if the heating on the control panel (Danfoss FP715) is set to off; if i switch the power off to the control panel the relay goes silent. Probably an obvious statement but may help!
Oddly the relay chatter stopped for about 24 hours and the heating worked fine, then it went AWOL again. I installed the thermostat around 9 years ago; the relay and control panel are probably at least 14-15 years old. I'm hoping this is just a need to replace the thermostat or relay but can happily cope with replacing the control panel if needed; I wanted to rule the possibility that the fault isn't somewhere else but manifesting as relay chatter.
Any advise on further diagnosis appreciated!
Cheers
When I adjusting the thermostat (Drayton RTS8, running on 24vdc) to kick the heating in to life results in relay chatter (he relay in in a separate box so easy to access and is the same as this one: IMO RS2PN 12DC IMO DPCO 10A 12DC RELAY | Kempston Controls - https://www.kempstoncontrols.co.uk/RS2PN-12DC/IMO/sku/428124). I'm no engineer but I'm guessing the thermostat throws the relay (assuming the usual timer / control panel heating is in the switched on position) which kicks a control board into supplying the boiler and valve serving the radiator circuit with a "go for it" ... and voila...heat. Something is getting in the way of that!
I've thrown a multi-meter across the thermostat (2-wire install) and its showing around 24Vdc when "not on" which drops to around 1.5-2Vdc when the temperature is turned up, at which point the relay goes nuts. I don't know if the second voltage is around the right level.
As a workaround I can flick the relay into test mode at which point the valve serving the radiators opens; thought this at least serves as a check the relay hasn't completely failed (although the chattering probably rules out a complete failure). Current workaround to obtain heat is to switch on the hot water and manually open the heating value but that only works as long as the cylinder thermostat doesn't feedback to shut it off when the water is at temperature.
Also to note is that the relay chatter is present once it the thermostat is turned up until it "clicks on" even if the heating on the control panel (Danfoss FP715) is set to off; if i switch the power off to the control panel the relay goes silent. Probably an obvious statement but may help!
Oddly the relay chatter stopped for about 24 hours and the heating worked fine, then it went AWOL again. I installed the thermostat around 9 years ago; the relay and control panel are probably at least 14-15 years old. I'm hoping this is just a need to replace the thermostat or relay but can happily cope with replacing the control panel if needed; I wanted to rule the possibility that the fault isn't somewhere else but manifesting as relay chatter.
Any advise on further diagnosis appreciated!
Cheers
