whats wrong with my central heating

[askpin]

my central heating can run for days then one morning im waking up to a cold house and im getting the red flashing light on my potterton suprima 40l.

when i press the reset button on the boiler, the boiler comes back on but i soon hear the water running through the boiler as if it were getting really hot or as if the water pressure has dropped and it switches off again to red flashing light.

if i switch the system off and leave it for a day i can normally switch it back on and it will run for a few days, but eventually will switch off again with the symptoms above.

i have bled the radiators several times, most of the time there is no air but sometimes i will get a bit of air locked in one of the radiators.

the problem started a couple of years ago, and we have had the pump replaced and another part sorry cant remember what the engineer called it, think it was a valve.

but with it being cold outside just now the boiler seems to be really struggling, the colder it gets outside the more the boiler is switching off and flashing red.

any help would be greatly appreciated! cheers

 

[Madrab]

Does the green light stay on when the red one comes on or does the green light go out? Does it flash a couple of times a sec maybe?

Looks like its time to get the RGI in...

 

[askpin]

99% of the time the green light goes out and only the red light is flashing, it flashes constantly rather than a few times in a minute.

today i did notice the red light was flashing but the green light was on solid too but boiler was off.

when the green light is out and the red light is flashing the water pump still stays on even though the boiler has locked out

 

[Madrab]

If the green light goes out then it's a full lockout then you may be into combustion chamber/overheat territory.

As suggested time for the RGI methinks.

 

[askpin]

If the green light goes out then it's a full lockout then you may be into combustion chamber/overheat territory.

As suggested time for the RGI methinks.

Hi

Sorry I should have said in my first post. The boiler is kettling too.

If I put just the central heating on, the boiler kettles after about 5 mins, no loud bangs but definitely a whistling sound like an old kettle.

If I then switch the hot water on the kettling goes away after a few seconds.

I suspect the problem may be caused by insufficient water flow when the boiler is working on central heating only. With both central heating and hot water demand, there is enough flow to operate the boiler normally.

Ive already had 2 different engineers out from BG but they haven't fixed it.

 

[Agile]

the problem started a couple of years ago, and we have had the pump replaced and another part sorry cant remember what the engineer called it, think it was a valve.

Might be worth searching here for how to check the flow is the correct way round!

Also check any header tank is correct. See FAQ here.

Tony

 

[askpin]

does this look ok? i think the pump was put on the same way as the old one but the old one was a different model from this.

cheers