Boiler issues not firing after refill

[Notagainpike]

Hi all...got some issues....drained my working ok system yesterday to upgrade some 15 to 22 on the flow and return rad circuit.
Refilled and bled up.
Fired boiler up, had hot water and rads for 3-4 hours...
Turned off to cool.
Boiler would not fire on timer later, demand wouldnt work either....
Noticed that the pump when working did sound like it was passing bubbles...if that makes sense...?
Also, boiler temp was very high, and heat exchanger was boiling hot to touch.
This morning no hot water or heating on timer fired boiler, so i switched both to demand, i think the boiler woke up, but temp went from 30s to 102 in a couple of minutes.....

Last night i cracked the bleed nipple at the bottom of the heat exchanger and there was water present.

Im assuming i have air locked boiler?

I never had any problems like this with the gravity fed system....

 

[fowlerboi]

99% sure it will be air

Check to ensure heat exchanger is vented, system filter too (I've had systems where nearly all air is caught in the filter and it takes ages to keep bleeding it waiting and then repeat). Once everything is vented properly then you need to start getting some flow moving and the pump will soon clear the air. Start with your hot water only.

If your boiler isn't firing still and it sounds like the pump is cavitating then unplug the connector for a second or 2 or hold the switch between 2 different speeds to stall it, this will let the air escape and allow the pump to keep trying to clear the air.

If you have no luck with the hot water (I had one this week) then run the heating only and shut down every radiator but one, if you have a Y plan make sure you turn your cyl stat down to ensure the valve shuts the hot water. Then go round once and turn a new rad on and the old one off each time they get hot, then finally introduce the hot water.

A photo of your pump and pipe work in the airing cupboard may help too

 

[ShaunCorbs]

Yep air locked try running on hot water only if you have a cylinder

 

[Notagainpike]

99% sure it will be air

Check to ensure heat exchanger is vented, system filter too (I've had systems where nearly all air is caught in the filter and it takes ages to keep bleeding it waiting and then repeat). Once everything is vented properly then you need to start getting some flow moving and the pump will soon clear the air. Start with your hot water only.

If your boiler isn't firing still and it sounds like the pump is cavitating then unplug the connector for a second or 2 or hold the switch between 2 different speeds to stall it, this will let the air escape and allow the pump to keep trying to clear the air.

If you have no luck with the hot water (I had one this week) then run the heating only and shut down every radiator but one, if you have a Y plan make sure you turn your cyl stat down to ensure the valve shuts the hot water. Then go round once and turn a new rad on and the old one off each time they get hot, then finally introduce the hot water.

A photo of your pump and pipe work in the airing cupboard may help too

OK...heat exchanger vented as in....?

 

[Deleted member 120897]

Vented all manual/auto air vents?

 

[SimonG]

Definitely air. Bleed everything you can find and can also try putting mains water onto drain off and back fill. Careful though, you don't want to flood the f&e tank.

 

[Notagainpike]

Yep air locked try running on hot water only if you have a cylinder

Tried this just now....no joy

 

[Notagainpike]

Vented all manual/auto air vents?

Bled all rads and vent up by new cylinder...

 

[Notagainpike]

Definitely air. Bleed everything you can find and can also try putting mains water onto drain off and back fill. Careful though, you don't want to flood the f&e tank.

Just got rid od f+e tank...now sealed system....

 

[Notagainpike]

99% sure it will be air

Check to ensure heat exchanger is vented, system filter too (I've had systems where nearly all air is caught in the filter and it takes ages to keep bleeding it waiting and then repeat). Once everything is vented properly then you need to start getting some flow moving and the pump will soon clear the air. Start with your hot water only.

If your boiler isn't firing still and it sounds like the pump is cavitating then unplug the connector for a second or 2 or hold the switch between 2 different speeds to stall it, this will let the air escape and allow the pump to keep trying to clear the air.

If you have no luck with the hot water (I had one this week) then run the heating only and shut down every radiator but one, if you have a Y plan make sure you turn your cyl stat down to ensure the valve shuts the hot water. Then go round once and turn a new rad on and the old one off each time they get hot, then finally introduce the hot water.

A photo of your pump and pipe work in the airing cupboard may help too

Il put a pic up