Airlock?

[MickyP10]

As mentioned in an earlier thread we've just moved into a nine year old house and I've been draining the brown tar like substance from the heating system (See 'Flush' post a day or so ago). Things were going fine but the filling loop leaked badly from a valve spindle whenever I topped up the pressure. So today I replaced this with a view to carrying on draining/flushing, etc, but now it seems I have a massive airlock in the pump/cylinder area. All radiators are bled but only the landing one tries to get hot, then boiler (Ideal Icos HE12) shuts down.

Pump is an Alpha 2 with a digital display. It used to display 45watts but now it's 13 and quite warm. The older pumps had a bleed screw but this one doesn't appear to.

Any thoughts? I've opened up the upstairs lock valves. Can you bleed these pumps anyway?

Or would manually switching a motorised valve help shift some air?

I did phone Ideal but was getting nowhere after 20 mins. Then again, I don't think it's a boiler fault.

 

[oldbutnotdead]

Have you latched the motorised valves open? Yes when draining/filling you need to o do that. Which upstairs lock valves have you opened?

 

[MickyP10]

Hi and thanks for reply.

Not manually opened motorised valves - didn't want to dig myself further into mire! However, the white plastic one in foreground has a manual lever at front which has no markings; another lever on left-hand side, marked A and B and another tiny lever on right, which I can't see properly. It has nothing written on it.

On the metal Honeywell F-80644 valve on top in pic it says 'Auto' and 'Manual'.

Valves I opened up were radiator valves. I thought by some miracle it might help!

 

[oldbutnotdead]

The top (Honeywell) is easy- push the lever in the direction of across the pipe all the way over, then lift it up slightly and let it relax into the notch in the casing. Can't help on the placcie one...
Yes opening lockshields can help when bleeding but you need to note how many turns they took to open fully (otherwise you can end up with an unbalanced system).
Sludge in a 9 year old system is disturbing...

 

[MickyP10]

Thanks again.

OK, I'll try that. To confirm, I crank the lever over and fire up the boiler again? Then flip it back over to auto after airlock clears, if it does. And is there any mileage in shutting off downstairs TRVs to help give it more oomph upstairs?

 

[oldbutnotdead]

You don't want the boiler firing yet, just the pump. This is a pressurised system, no f & e tank in the loft?

 

[MickyP10]

Pump doesn't seem to operate without boiler kicking in too - unless I'm being very silly. I mean, turn wall thermostat up = nothing at pump. Turn thermostat up and boiler on = pump runs and boiler fires for short while.

There has been some gurgles and success - I now have three radiators upstairs which are getting warm.

This is pressurised and no tanks in loft.

Thanks for your help.

 

[oldbutnotdead]

Depending on the boiler (mainly how clever it is) you could just turn the gas off to it- this used to work ok on older boilers, not sure how good an idea it is on modern ones. Hopefully someone more current will advise...

 

[terryplumb]

Have you latched both valves open ?
Are their any air bleed valves on the system that need manually bleeding ?
What is the pressure in the system ?
Have you fully bled air from every radiator and the hot water cylinders coil ?
Close the TRV'' on the 3 rads that heat up.

 

[MickyP10]

Thanks both. After much sploshing and gurgling it's coming back. Thank you!