Assuming that the PCB is ok and that I have all the necessary power and start-up sequence working you stated that it must be a fault in the boiler. Sorry forgot to say I looked at the fault finding diagram about 2 weeks ago which is why I agreed to purchase the new PCB.
So in conclusion...
So Meldrews_mate. Thanks for the advice. i went throough your step by step guide and the answer to the first 4 questions, everything was as you said. All working. So this leads me to a boiler fault which is where my question comes from earlier. What on the boiler can prevent the switched live...
i can see where you are going with this but when the fault happens it effects both HW and CH. The valves open even when the fault occurs and send the SL back to the boiler.
I here the click as you mentioned when the HW or CH is turned on both valve operate but the boiler just will not fire up...
Thats all very well but it makes no deference if you have replaced these items already. My system is beginning to be a bit like "triggers broom".
It came back on again about 5 hours after it went off. There doesn't seem to be ny pattern to this though.
Tried calling Potterton again...
Well it’s off again. This time the faulty thermostat has been replaced along with both of the 2 way valves. Yesterday the heating developed the original fault. No HW and No CH.
I have again checked the valves, pump and all the electrics which all seem to work fine. I have tested the Boiler...
You are correct. My mistake. I am learning what’s what so please bear with me. I have 2 way valves.
Last Night I when home and switched the HW to the on position on the timer control. I then went to the 2 way valve and manually switched it to the on position. I had hot water and CH. I am not...
I presume you are talking about the motorised valves.
I have two located in by the pump. i switched both to manual but nothing happened.? Do you think this is the problem? They are Honeywell F4-9517 models.
Dan
Strange thing is The PCB was replaced a week ago and this made no difference. Are you suggesting that I should speak to another Plumber? The one that came round was a corgi-registered plumber? If you are saying that the boiler is pretty simple then do you think the problem could be the...
Christmas Eve my boiler started playing games. The hot water and central heating would just stop. When the boiler was fired up it made clicking noises and the fan started. That was it. If you left it alone for maybe 4-8 hours it would come back to life. So a cold Christmas... I eventually got a...
Christmas Eve my boiler started playing games. The hot water and central heating would just stop. When the boiler was fired up it made clicking noises and the fan started. That was it. If you left it alone for maybe 4-8 hours it would come back to life. So a cold Christmas... I eventually got a...