Baxi 80e

[csim]

I know this is a long shot but wondered if anyone could give me some advice with my boiler please?
I have a baxi combi 80e, and I had the motherboard replaced about 2 months ago, after a year of intermittent heat and hot water. It always flashed with a fan or flue problem, but none could be found, but eventually they diagnosed the motherboard and I had hot water!

Now its failing again. the boiler is trying to turn on, but the pilot light is not trying to ignite. Something starts whirring inside- I think it is the pum from when i opened it up, could feel vibrations on that but not the fan. After about 15-20 seconds, the pump stops moving, the radiator light comes on and the 60 degree light starts flashing, apparently signalling a pump or pressure problem.

Occasionally-i.e. once every 3 days-it all just comes on immedietly after I turn it on, and works perfectly fine for 12 hours, before flashing again.

I have bled the radiators and checked the pressure on the boiler, and checked the air pressure screw is open, and they are all fine.

I would really appreciate any help anyone can give me. I don't know hardly anything about boilers at all, but I can't afford to get a plumber in until after christmas, and we have another big freeze heading our way the next few days. so thought I would see if there is anything I could do myself.

Thanks very much!
Claire

 

[twgas]

what was the system pressure when you checked it?

 

[csim]

Around 1 when cold, goes to 1.5-2 when hot

 

[twgas]

when you turn the heating on does the pump proving switch activate, its on the left, behind the control panel, there's a spindle should rise and make the switch.

 

[csim]

No, not as far as I can see. When I turn it out on the only thing moving or doing anything is the pumb starts whirring.

 

[twgas]

try turning the heating on then, using a piece of plastic (so as not to touch electrics), lift the switch lever on top of flow switch. Does this make the boiler fire?

 

[csim]

No. It lit up the water side instead and still didnt try to light anyting, still flashed the pump/pressure problem. Thank you for trying to help me!

 

[csim]

Actually, I'm just going to check I did the right one first with you! Small box on the left, behind the boiler/hw dial,2 connecting wires. Lever was at the bottom, not the top. This sound right?

 

[twgas]

if you run hot tap a spindle should move toward you, making a switch (green wires) and turning pump on.
the heating spindle is further back and above but also operates a similar switch but upwards.(red wires) this is the one that senses pump running and lets the sequence continue to next stage. each of the two switches a pair of wires to it.

 

[csim]

I was looking at the wrong one, sorry! done that one, not moving either and doesn't fire up when I press it up manually.

 

[twgas]

make sure the CH is on at both the timer and room stat. do you get any noises starting when you raise the switch, can you hear the switch clicking.

 

[csim]

I THINK ITS WORKING!! Sorry, got a bit excited there! The pin which pushes the lever up and down was up part of the way all the time. The piece of plastic I used knocked a tiny piece of rust or muck out of the way, and the next time it fired up instantly. Just turned it off and on again, and it worked again.

Thank you so much for your help, fingers crossed it stays working!

 

[twgas]

no probs, hope you have a warm xmas, although scale/crud on the pin is usually a sign of the spindle/gland starting to fail so keep an eye on it.