I hope I can help you today, My name is Ivor.
You say that you changed a radiator, did you after filling and running the system, then bleed radiators to get any excess air out.
Yes, fully bled the system from the radiators and a bleed valve above the pump.
Ok thanks, XXXXX XXXXX have a water pressure dial or similar, this should show about 1.5 to 2 bar, this will eneble the pressure switch to operate.
Its a vented system
I would suspect that the water pressure is low. Ok have you tried to put more water into the system and see if that operates the boiler on heat?
Another idea is to shut down all radiators except one and see if that then fires the boiler up.
Just checked water tank in loft, completely full. I'll try the radiators now.
thanks I will hang on for you.
Okay, tried that. No luck, the system is not even firing up. Even though I put timer on 'constant' and turn thermostat right up, the pump does not engage and the bolier does not fire up. I'm thinking possibly some sort of electrical problem possibly...... not sure.
Hello again is the pump running?
Are you able to see if you have power there, is ther a fused spur
Sorry bad typing.
The pump runs for the hot water side of system but does not for heating.
Another idea there should be a 2 or 3 port valve nearby to the pump can you operate this by hand and see if that works.
I'll try it now, is this the diverter valve, little silver box on top of pump?
Yes that is correct there maybe a small lever you could try to move
Yes, I have done this, sorry, no joy. No change at all.
Let me recap, all the system has been refilled and radiators bled. The pump is running on hot water so the power is there. You have tried operating the valve all to no avail. But before you changed the radiator it was working fine. Is that correct.
Yes, everything is correct except that the heating system worked fine after the initial system fill on Saturday.
I now suspect that there maybe a problem with the pressure switch within the boiler or the signal from the thermostat is not getting there.
When you changed the radiator what did you do? did you shut it all down and turn the input water valve off?
All I did was tied up the ball valve in the header tank and drained the system, I did not turn any valves off around the hot water tank because I knew I would forget to re-open them.
thanks, XXXXX XXXXX you say I would still suspect that either there is an air lock which is not letting the water flow or it is the pressure switch.
If it's the pressure switch, that's an Engineer's job isn't it?
yes I am afraid that would be the case. One last thing Could you re drain the system from start on Saturday. then make sure water is getting to all the radiators, bleed the system of air, make sure water is getting to the boiler etc.
If you would like me to opt out and open the question to another expert I will do that for you, before spending money on an engineer visit.
No it's okay, I'll have to try that tomorrow as I do not have all my tools with me today to drain the system and re-fill. I'll try draining first and re-filling, if that doesn't work, I'll have to seek an Engineer. Thanks very much for your help Ivor.
My pleasure I hope that you get it sorted soon.