alpha 280p no heating!

[kjc63]

I have an Alpha 280p combi boiler about 6 years old. The hot water is working ok but the heating is not coming on properly. I have had an engineer out twice who has changed a therm switch and also put cleanser and another liquid through (yesterday). When I put the heating on the green heating display light comes on and the boiler fires up but the rads are not all getting hot. Just before this problem started we had a real banging noise and airplane noise! HELP im cold

 

[ChrisR]

Did he check the pump?

 

[kjc63]

He didnt actually check it to my knowledge but did say that it seems to be running okay!!

 

[ChrisR]

It could be blocked or going slow. Has to come off for inspection.

 

[Gasguru]

Blocked return filter?

 

[kjc63]

Thanks for the info - will have a chat with bloke when he comes. Put heating on 1 hour ago and there seem to be a few radiators upstairs that have come on but not really hot! Boiler seems to be powering up on the heating for less that a min and then powers down again - keeps doing it!! Powers up perfectly for hot water. The guy did say that he may put some acid in system?? Whats that all about?

 

[Jenks_c]

Does your system have a motorised valve? (probably sited near the pump) if so, it could be faulty, you should be able to operate it by hand.

 

[dotto]

Does your system have a motorised valve? (probably sited near the pump) if so, it could be faulty, you should be able to operate it by hand.

If it was a faulty pump and you opened the hot tap, your boiler would go into lock out after a while because it would overheat.........having said that there are people more experienced than me on this forum, so keep an open mind!