Hey all,
Recently the Honeywell V4073A 3 port valve in the air cupboard has starting making loud screeching noises and the system is also not operating as it should. I've noticed that the Radiators are not getting hot but just warm and the thermostat isn't having any effect on switching boiller on when it should. Sometimes when the system timer goes off the noise stops, sometimes it doesn't and I have to power down the system to stop the noise
With just hot water on there is flow going to the radiators and when the HW reaches temperature than the valve starts screeching the pump stays on but the boiler switches off.
When the system is on both HW and CH and when the HW reaches temperature the valve starts screeching, the boiler switches off but the pump keeps running.
When the system is on CH the valve starts screeching the pump is off and boiler is off. Adjusting the thermostat has no effect.
My suspicion is it's just the valve head - something electrial gone wrong - maybe it's just the motor. The lever on the side is fully slack all the time no matter the system setting (HW or CH). 'Course actual valve could be seized? This system is probably 20 years old so that's possible.
How would I diagnose this. I am capable of changing the head myself but the valve would need a plumber to do it. I did once change the innards of a Drayton before they came out with the detachable head model so the head part I can manage.
Appreciate any advice.
Thanks.
S
Recently the Honeywell V4073A 3 port valve in the air cupboard has starting making loud screeching noises and the system is also not operating as it should. I've noticed that the Radiators are not getting hot but just warm and the thermostat isn't having any effect on switching boiller on when it should. Sometimes when the system timer goes off the noise stops, sometimes it doesn't and I have to power down the system to stop the noise
With just hot water on there is flow going to the radiators and when the HW reaches temperature than the valve starts screeching the pump stays on but the boiler switches off.
When the system is on both HW and CH and when the HW reaches temperature the valve starts screeching, the boiler switches off but the pump keeps running.
When the system is on CH the valve starts screeching the pump is off and boiler is off. Adjusting the thermostat has no effect.
My suspicion is it's just the valve head - something electrial gone wrong - maybe it's just the motor. The lever on the side is fully slack all the time no matter the system setting (HW or CH). 'Course actual valve could be seized? This system is probably 20 years old so that's possible.
How would I diagnose this. I am capable of changing the head myself but the valve would need a plumber to do it. I did once change the innards of a Drayton before they came out with the detachable head model so the head part I can manage.
Appreciate any advice.
Thanks.
S
