No hot water after bleeding CH pump

[spooky_b329]

hmmmm...chickened out on that one. Only 'spanner' I have big enough is a monkey wrench and that is struggling to fit. Plus there is virtually no room behind there...might have to call on the British Gas cover and let them sort it, unless I see the plumber bloke that parks in our street and he is feeling helpful.

 

[hi-spec plumbing heating]

ok but i would say an airlock or gravity check valve stuck.

 

[spooky_b329]

Balls...think the CH pump needs bleeding again as radiators have got lukewarm but not hot, and pump casing has got much hotter than surrounding pipes. Also pump is making the same trickling noise as it did yesterday before I bled it.

 

[hi-spec plumbing heating]

least you know how to do it now. no harm in trying

 

[spooky_b329]

i agree.
but you drained system so your coil in tank would of emptyed the when you refilled the valve was shut which would of caused air to trap.

Reading the above comment, would draining the system again and then refilling whilst setting the valve to manual help to avoid an airlock developing in the cylinder coil?

British Gas can come out under our Homecare agreement by Friday but I'd rather get it working myself rather than have them potentially recommending that I have various modifications/powerflushes done to the system and then excluding cover for related problems until these recommendations have been acted on. (Can you tell I've been reading the T&C's? )

I've got the day off tomorrow so have plenty of time to faff around trying to get it working, rather than try and sneak out of work early to meet a BG engineer on Friday afternoon.

And thanks for your help so far.

 

[hi-spec plumbing heating]

did you get the heating working.

 

[spooky_b329]

I cracked the same nut as yesterday on the outflow side of the pump and didn't get any air, just water dripping. (didn't undo it very much but still, air would escape before water would it not?) Radiators and pipes either side of the pump remain cold.

When I first got in this afternoon, I set controls for hot water and pipework to rear of boiler got hot but no hot water, then later I turned on central heating. Radiators seemed to get the residual hot water that was left in the pipes around the boiler (if I remember correctly the pipes passing through the pump and into the floor were hot) and got slightly warm, but then the boiler shut down and since then I've had no central heating or hot water. Boiler will fire up for short periods but then shuts down.

 

[hi-spec plumbing heating]

sounds like theres air back around the pump area.
check the pump is working.
if it is theres not no reason why what you done, slacken the nut, don't shift the air again tonight. them old system can be a pain to bleed with no air valves.

 

[spooky_b329]

Thanks will give it another go tomorrow. As long as the system is cold I assume there is nothing wrong with loosening the fitting on the inlet side of the pump?

Finally, if this still fails, would my suggestion of draining the system and refilling whilst the valve is set to manual be worth trying? Would I need to push the valve over to manual whilst the motor is resisting or does it have exactly the same effect if I do it when there is no pressure?

 

[hi-spec plumbing heating]

yes give it a go. put the valve in man

 

[spooky_b329]

OK an update.

Everything had cooled down so fired it up again. None of the pipes get warm at all, except where they are close to the flue. So possibly this means that the problem isn't an airlock in the cylinder coil or thereabouts. Pipes were pretty hot earlier but this may have been due to them being heated externally.

I'm assuming the pump is still free of air as when it started up I heard water moving in the radiator next to me.

I'm stumped. Girlfriend is boiling the kettle to have a sponge down bath

 

[spooky_b329]

bump

 

[spooky_b329]

OK still no luck with the boiler this morning so moved the auto valve to manual, drained down and refilled, bleeding rads and then bleeding CH pump of air.

Fired the thing up, nothing happened hot water wise for the first 15 minutes but now have hot water circulating thru the cylinder My question is, should I leave the hot water on for a few hours by itself, or turn on the central heating now?

After I last drained it, I had hot water, then bled the pump and had central heating, but after that I couldn't get hot water. Then the central heating stopped working as well.

Don't want to go through the whole draining process again so what should I do?

 

[hi-spec plumbing heating]

try the heating as well as hot water.
as your hot water is gravity not pump on it own circuit.

 

[spooky_b329]

Fingers crossed...

I've got a mountain of washing up to do