Central Heating not working...airlock?

[Michelle1972]

Hello,

I'm after some expert advice and this seems a good site to get some help on why my heating is playing up so much.
Firstly the under floor heating pipes have been juddering really often and loud, making me believe there is an air lock somewhere? This morning I got up and could hear the heating was working (all pipes in bathroom cupboard hot), but rads were freezing.
After switching the system off I bled all rads (although no air came out) and this seems to have done the trick for now but this keeps happening and its no fun.
My boiler is in the loft so not the easiest of places to get to. There are 2 tanks up there too, one is larger with cold water the other is small and I think had very hot water in it....is that one supplying the heating system? I topped up both by pushing down on the ball cock....not sure if that would help push the water through the system?

Do you think I need to get someone out.....I mean do you think this is a serious problem?

 

[Puddle]

Sounds like you should get someone in to check it out,especially as winter seems to have arrived with vengeance ,could be over heating or motorised valves could be faulty,as said get someone in or could cause more damage in the long run

 

[PuraTherm]

Dose sound like air lock. The problem with having the boiler in the loft is that there isn't much head pressure from the tank. The system has trouble moving the air from the pipes. Sounds like the boiler and the tank are close to one another. The warm water in the tank is usally caused by pump over. This is where the pump moves ome of the water back into the tank. Next time you bleed it leave the system running. This will help move the air. If there is a bleed off in the loft then you want to vent from there as well as all the rads. You should get an engineer in to service the boiler and give the system a check.

 

[Michelle1972]

Thanks for advice guys....not sure what you mean by 'leave system running'? Do you mean leave the heating and water on?Not sure either what you mean by 'bleed off in the loft and vent fron there'??
I have a frost thermostat in the loft which came on automatically so I've altered the temp on that...that could cause it too over heat? As for a plumber any recommendations? I'm living in the West Midlands and don't want a cowboy in.
Pipes are banging again....looks like might have to bleed rads again. How does air get in the system anyway?? I must sound really thick...all advice is greatly appreciated

 

[PuraTherm]

No. You don't sound thick. That is my fault. I'm used to speaking to people who are in the industry. Leave the heating system on and running. The "bleed off" means somewhere you can vent the air from the system. There might be one in the loft space. The frost stat wouldn't cause the boiler to over heat so you are ok there but if you have lowered the temprature on it too much then the pipes could freeze. Call Andy Lanagan with A3S, he is just outside of Worcester. 07825289100. Tell him Keith says hi.