Need help purging central heating

[dm65]

Bl**dy plumbers, who'd have em ? :wink:

Had a new boiler fitted which hasn't gone so well - 2 bad leaks (mini floods into living room) but now, after 5 return visits, everything's dry but we are no longer getting heating on the ground floor
Upstairs is fine, radiators are nice and hot but cannot get heat downstairs - all radiators bled, new pump fitted and also had a replacement electronic valve doodah near the pump (been told its for hot water or heating)
Today, I've been on 't floor draining water from that little drain tap thing at the bottom of the radiator - lots of air comes out but I've been doing this repeatedly, perhaps 3 times on each rad (there are 5) and this is into a 3 gal bucket so must have flushed the entire system more than once now
Immediately after draining, the rads are hot but then cool down again
Can anyone PLEASE give me some idea of what to try as we currently unable to get hold of the bl**dy plumber again

 

[RogerS]

You don't drain the water from the bottom. There is a small vent at the top of the radiator to let the air out. Google 'bleeding radiators'

 

[Graham Orm]

If it's air locked try filling it through the drain valve very slowly with a hose connected to the cold tap. The other option is to boil it through, but I don't feel comfortable telling you how to do it as it's unorthodox.
As already stated you bleed air from the top of the rads.

 

[dm65]

Cheers Roger, but all radiators bled, the ones that are working are hot top and bottom, the ones that aren't don't even get heat to the pipes that feed them until I use that drain plug

Wasn't clear when I said 'draining from the bottom' - this is from a drain on the pipework itself as it comes in (or out) to the rad

 

[dm65]

Cheers Grayorm

As I said, I've already bled each rad and they are uniformly hot or cold (also one of the too-few plumbing jobs I am familiar with)

I have just been reading about balancing radiators so have just reduced the flow to the end that doesn't have the thermostat (right out of technical terms - sorry) on the rads that heat up first and will see if this produces any heat downstairs

 

[Graham Orm]

Were there any rads added to the system?

 

[dm65]

Were there any rads added to the system?

None and all worked fine before

Only boiler replaced though needed a new hot water tank after one the pipes broke while modding pipework (at same time) - this was flood #1

Oh and we have some sort of header tank in the loft now as well which we didn't have before

Just poured myself a glass of this http://www.jurawhisky.com/our-whiskies/diurach as I don't want to be too cold watching Norm in a minute

 

[Graham Orm]

Why the new tank in the loft? Did you have a fortic cylinder (cold tank on top of cylinder all in one unit) replaced with a conventional one?

 

[Graham Orm]

Turn off the rads that are hot completely and see if the others warm up. If they do start turning the others on in slow increments.

 

[dm65]

This is what I have been draining and run it until the rad gets hot but get quite a bit of air out each time

 

[Graham Orm]

This is what I have been draining and run it until the rad gets hot but get quite a bit of air out each time

Have you bled them from the top? That is a drain valve not for bleeding.

 

[dm65]

Why the new tank in the loft? Did you have a fortic cylinder (cold tank on top of cylinder all in one unit) replaced with a conventional one?

You're either from one of those foreign part of the uk or you just threatened me (might as well have done anyway for all that I understood of your question )

 

[nev]

I had a stubborn rad once that would not bleed. a plumber friend came up with a solution and fingers crossed no problems since.
the solution was to fully close the return / out? valve (the one without the trv) on all the rads, put the heating on an then bleed the problem one conventionally. Then re open all the others.

 

[dm65]

Have you bled them from the top? That is a drain valve not for bleeding.

Honestly, yes, more than once and if I do that now, I get instant cold water

I also (now) know it is a drain valve but this will at least let me flush out the cold (and filthy, or used to be) water and fill the rad, to the very top, with nice hot water but then it just cools down again

 

[Graham Orm]

Close off all the rads upstairs completely

 

[Graham Orm]

What channel is Norm on?

 

[dm65]

Close off all the rads upstairs completely

Sorry Grayorm, I am hopeless with this - is that NOT from the thermostat, ie 't other end with the turny flat bar thing that I need to borrow a cap from another rad for ? (must be a techy term or acronym for that)

Whats a trv Nev ? - is that the valve with the thermostat ?

Norms building a greenhouse on sky 242

 

[Graham Orm]

Either end will do as long as you shut it down.

 

[Graham Orm]

Yes found Norm thanks, have seen that one.

 

[Graham Orm]

One end is TRV Thermostatic Rad Valve the other end is a lockshield (a simple valve with no thermostat).