Need help purging central heating

[Chrispy]

Have you checked the control valves on 5he rads? Sometimes they stick when not used for a while, the top piece should come off to expose a pin inside tap this untill it moves freely (it is spring loaded) without the top on the valve should be fully open so the rad should warm up.

Also if you have a new boiler is it a condensing type? I thought if these were fitted then the whole system should be power flushed to help prevent blockages in the new boiler heat exchanger, do you know if this was done?

Not a plumber just things that I have picked up over time.

 

[dm65]

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

Thanks - completely out of my depth with this

Believe it or not, I don't believe I've seen this particular NYW episode but that wouldn't stop me any way

Anyway, swimbo is settling down on her gold, sorry, going to bed, so I guess i'll just (potentially) freeze till tomorrow - still got whisky (no e) and dogs to walk - that'll keep me warm till then

 

[Graham Orm]

Good luck :wink: Get the firm back tomorrow.

 

[dm65]

Have you checked the control valves on 5he rads? Sometimes they stick when not used for a while, the top piece should come off to expose a pin inside tap this untill it moves freely (it is spring loaded) without the top on the valve should be fully open so the rad should warm up.

Also if you have a new boiler is it a condensing type? I thought if these were fitted then the whole system should be power flushed to help prevent blockages in the new boiler heat exchanger, do you know if this was done?

Not a plumber just things that I have picked up over time.

Cheers Chrispy, checked the pin on one of the cold rads - moves freely

Sorry, don't know what type of boiler either but will ask the plumber when we find him - last thing he mentioned on Sunday was power flushing then he scarpered but I now know there's a lot of that black sludge in these downstairs pipes, much reduced now by my constant draining

 

[dm65]

Good luck :wink: Get the firm back tomorrow.

Don't worry, he's coming back when we can get hold of him, I'd just like some heat now as the ch is our only source

 

[nev]

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 ?

Yep. Thermostatic radiator valve or in laymans terms the big turney knob with the numbers on

But like Grayorm says I think you should be able to do it at either end (i just did as i was told and it worked)
I suppose it just stops the water from moving through the system. so the only moving water is between the boiler and your troubled rad(s) so hopefully it takes the air with it when you bleed em.

 

[Lons]

He's not much cop as a c/h installer / plumber by the sound of it! The fact you have had major leaks would make me more than a little suspicious.

My immediate thought was that you have microbore but your photo suggests not however the same fault might be the cause and that is a possible "high spot" in the pipework which is trapping air and causing a lock which could be the reason you're bleeding air from the bottom valve which shouldn't happen as the air would normally rise to the top of the rad.

Existing pipework or not, the plumber may have installed the new boiler, pump and diverter valve incorrectly. Sounds like an extensive installation with a new header tank as well. The reason for me thinking microbore is because it's all to easy to let the pipe loop over say a joist causing the trap and is a common fault.

Has the position of the new pump changed from the previous one? It could well be sucking air into the system from a porous soldered or compression joint. These generally don't leak water so are hard to find.

The other possibility though unlikely due to the air being present is that the TRVs on the radiators are directional (most are now bi-directional) and have been fitted to the return instead of flow side of the rads.

My only other concern is why so much crud in the pipework? It should have been well flushed through before installing new boiler, pump etc as it will shorten their life.

I've assumed that because of the header tank, you have a standard boiler and not a combi which would be a sealed system. (If you are draining water from a sealed system without re-filling manually you will introduce significant amount of air and risk damage to the boiler and pump).

Bob

 

[dm65]

Yep. Thermostatic radiator valve or in laymans terms the big turney knob with the numbers on

Ah - why didn't you say that ?
Ok, so in the morning i'll zero all the big turney knobs with numbers upstairs and see what happens downstairs - I can feel when a rad needs bleeding and is a bit of an obvious test retrospectively (still way too clever for me though)

He's not much cop as a c/h installer / plumber by the sound of it! The fact you have had major leaks would make me more than a little suspicious.

First leak I can sympathise with - changing pipes to the hot water tank when one of the fittings on the tank broke (reputedly) - dung (ooh look, ukw changed my rude word) happens to even the best

Second leak - plumber removed front of pump and water gushed everywhere - he swears he turned the shutoff valve - whatever, this damaged the pump electrics and required another one which he fitted after draining the pipes first

My immediate thought was that you have microbore but your photo suggests not however the same fault might be the cause and that is a possible "high spot" in the pipework which is trapping air and causing a lock which could be the reason you're bleeding air from the bottom valve which shouldn't happen as the air would normally rise to the top of the rad.

Nah, standard 15mm been in situ for 15 years and the air thing is what prompted the post

Existing pipework or not, the plumber may have installed the new boiler, pump and diverter valve incorrectly. Sounds like an extensive installation with a new header tank as well.

Weeelllll, first plumber had to return day after fitting as the boiler kept tripping with an error code and he swapped over the two pipes that go into (or out of) the boiler saying he'd got them the wrong way round - I didn't call him a tool cos they're actually useful

Has the position of the new pump changed from the previous one? It could well be sucking air into the system from a porous soldered or compression joint. These generally don't leak water so are hard to find.

Pump looks to be in the same place and I have often wondered about air being brought in as I have to bleed certain rads each autumn when the heating gets turned back on I often have to bleed the pump when I hear it (running dry I assume)

The other possibility though unlikely due to the air being present is that the TRVs on the radiators are directional (most are now bi-directional) and have been fitted to the return instead of flow side of the rads.

Possible if the first plumber had actually done things right the first and then wrongly corrected it on his second visit ?

My only other concern is why so much crud in the pipework? It should have been well flushed through before installing new boiler, pump etc as it will shorten their life.

Plumber #3 intimated as much and a power flush was mentioned (Sunday) but he may well have been abducted by aliens now for all we know

I've assumed that because of the header tank, you have a standard boiler and not a combi which would be a sealed system. (If you are draining water from a sealed system without re-filling manually you will introduce significant amount of air and risk damage to the boiler and pump).

Ok, I understand that so mustn't be combi as the system fills back up again - must have removed about 20 gallon today and we only have 10 rads throughout

Quite a comprehensive reply Bob, thanks for taking the time and thanks to everyone else who has commented

 

[RogerS]

If your plumber fitted a new boiler without power cleaning which sounds as if you need it (comment re black sludge) then he is not a plumber but a cowboy. `new boilers have very narrow pathways inside that easily get blocked with the black sludge ..called haematite...and will almost certainly void your boiler warranty should you have a problem. You need something like a Magnaclean in your system to trap the haematite. Normal central heating inhibitor does not tackle haematite.

 

[Graham Orm]

From your description of his antics it sounds to me like he hasn't done many before. Is he Gas Safe registered? How did you find him?

 

[dm65]

Good morning chaps and chapesses

On waking (eventually as I am on holiday) I have turned off all upstairs pipes with the big turney knob with the numbers on and have heat to all pipes downstairs EXCEPT the kitchen rad which is physically closest to the boiler but I guess its at the end of the circuit ?

This is only receiving luke warm water to the pipes so the rad is, funnily enough, only luke warm - should I drain that one do you think ?

We also have two rads in the living room, one large (54") and one small (34") and the larger one is only heating the upper half of the rad - drain that one as well ?

Any further advice welcome as swimbo will want the rads back on tomight

 

[Graham Orm]

At this stage I think you need to get the company back ASAP. If not open one rad at a time upstairs, first half way, then fully. If that gets hot and the ones downstairs stay hot then move to the next one etc etc. When the ground floor rads start going cooler turn down the upstairs rads until they start getting hot again. The fact that they got hot downstairs probably means that the system does need balancing, although it shouldn't!
The cold rad could be because of an air lock or sludge or a valve stuck/left shut mistakenly.
When you say 'you have heat' is that warm or hot?

 

[Graham Orm]

Is there a room stat somewhere? If so it needs turning right up.

 

[Graham Orm]

Have to go out now good luck with it, get the clown back who did the boiler!!

 

[MMUK]

I'd also be drafting out a letter for Trading Standards and my solicitor about now......

 

[RogerS]

Did you get a certificate from him as you will need it if/when you come to sell your house.

 

[Chrispy]

Did you get a certificate from him as you will need it if/when you come to sell your house.

If he's selling his house I think he better delete this thread as well!!!!

 

[dm65]

An update - plumber is coming back to flush the downstairs rads but I think he'll be too late as I drained the two cold rads this morning and the water is clean now after yesterday

Draining these didn't help, rads got hot and then cooled down again, so turned the bathroom rad back on (upstairs) and downstairs started cooling down again

Have now got all the rads on upstairs, but on each one, have closed the other end (non turny round thing with numbers on) and then opened back up by approx. 1 full turn and have still got heat downstairs, but different temp at each rad - so at least it won't be as cold down here

Just done the same thing on the smaller living room rad as this is at full temp and am waiting to see if the larger rad comes all the way up to temp - haven't yet managed to get the bottom of the rad as hot as the top

 

[RogerS]

You need (a) a plumber who knows what he talking about and certainly (b) a power flush and (c) get a Magnaclene fitted

 

[dm65]

You need (a) a plumber who knows what he talking about and certainly (b) a power flush and (c) get a Magnaclene fitted

Agreed and am now waiting for a date from them - same company but we've gone through 3 plumbers now, last one was appalled by the sludge and certainly talked the talk but he's also the one who made a borrocks/was unlucky when he changed the pump (second mini flood)

I've got two grundig pumps in the shed if anyone wants them - first one works fine but has been used for 15 years, second one has damaged electrics from the torrent that ensued while fitting it !