Plumbing help!!! Rads not heating after draining - SORTED!

[TrimTheKing]

Did you check the zone valve, if fitted, for this particular part of the circuit?

Now you've gone past my knowledge

Zone valve you say?

 

[TrimTheKing]

matt

Just googled and now I know what a zone valve is

There is only on fitted, from memory, and it was working absolutely fine before I drained the system.

All the upstairs rads, including the leaky one, were boiling until I switched off the heating and bled it out, so I am assuming that it is still okay. How do I check?

 

[RogerS]

Do you know where it is located? Do you have access to it?

Things to check are ..

1) is it getting volts to turn it on

2) if it is then is it actually turning on.

The zone valves that I have feature a manual override. You can move this by hand and latch it in position. If it is getting electricity and has been enabled then this manual override will probably be very easy to move. That's probably one of the easiest ways to test for (1) and (2).

Is it a zone valve (ie on or off to one zone) or a diverter valve (ie routes ch water to either this zone or that zone)?

 

[TrimTheKing]

Do you know where it is located? Do you have access to it?

Things to check are ..

1) is it getting volts to turn it on

2) if it is then is it actually turning on.

The zone valves that I have feature a manual override. You can move this by hand and latch it in position. If it is getting electricity and has been enabled then this manual override will probably be very easy to move. That's probably one of the easiest ways to test for (1) and (2).

Is it a zone valve (ie on or off to one zone) or a diverter valve (ie routes ch water to either this zone or that zone)?

Yep, it is not far above the pump but I'm at work so can;t see it right now and can't remember where it is in the line.

Will be home around 19:00 tomorrow so after I've bathed and put baby to bed I will take a pic and post it up to help.

I know the 'latch' you are talking about, kind of spring loaded thing that 'relaxes' when it is on? That seems to be working okay as I checked that yesterday and when the heating was set to off you can still move it but it's very stiff and you can hear/feel the valve moving, but when the hearing's on it is slack and moves side to side easily.

Am I on the right track?

 

[head clansman]

hi

out of interest what internal size bore pipe has your system got ? is it by chance micro bore , any chance whilst sweating a new joint on the pipe it is now blocked with solder , turn on the heating and place hands either side of the replaced joint to test temperature .hc

 

[RogerS]

Do you know where it is located? Do you have access to it?

Things to check are ..

1) is it getting volts to turn it on

2) if it is then is it actually turning on.

The zone valves that I have feature a manual override. You can move this by hand and latch it in position. If it is getting electricity and has been enabled then this manual override will probably be very easy to move. That's probably one of the easiest ways to test for (1) and (2).

Is it a zone valve (ie on or off to one zone) or a diverter valve (ie routes ch water to either this zone or that zone)?

Yep, it is not far above the pump but I'm at work so can;t see it right now and can't remember where it is in the line.

Will be home around 19:00 tomorrow so after I've bathed and put baby to bed I will take a pic and post it up to help.

I know the 'latch' you are talking about, kind of spring loaded thing that 'relaxes' when it is on? That seems to be working okay as I checked that yesterday and when the heating was set to off you can still move it but it's very stiff and you can hear/feel the valve moving, but when the hearing's on it is slack and moves side to side easily.

Sounds as if it is working normally, Mark.

 

[TrimTheKing]

hi

out of interest what internal size bore pipe has your system got ? is it by chance micro bore , any chance whilst sweating a new joint on the pipe it is now blocked with solder , turn on the heating and place hands either side of the replaced joint to test temperature .hc

22mm (I think, haven;t measured it but from memory) copper from the boiler, rad flow/return legs are 12 or 15mm.

It's not just that rad that's not getting hot, the hot water isn't getting much past the pump next to the boiler

 

[Jake]

Is the pump working?

 

[RogerS]

Evening all

.......

Heating is now fired up and the downstairs underfloor heating is toasty again, the bathroom towel rails are boiling ......

Oh, do keep up, Jake !

 

[Jake]

Haven't read the whole thread, mea culpa. That seems to be slightly in conflict with what was just said about it not getting past the pump.

 

[TrimTheKing]

Haven't read the whole thread, mea culpa. That seems to be slightly in conflict with what was just said about it not getting past the pump.

Sorry my bad. It's getting past the pump to the underfloor (which goes horizontally) so it's actually flowing through the pump, but doesn't appear to be climbing the pipe to upstairs.

 

[Jake]

Can you isolate the UF and if so does that change anything?

 

[TrimTheKing]

Can you isolate the UF and if so does that change anything?

Yep, the system runs UF, upstairs towelrails/Megaflow and upstairs rads.

Have isolated both UF and TR/MF both together and independently but still no joy.

 

[RogerS]

I think we need to clear the decks and go back to first principles.

It is a pressurised system.

Looks as if there is an air-lock somehwre stopping three rads from heating up.

How about this for a suggestion?

Turn off the lockshields and TRVs on the 3 rads.

Turn off the TRVs on the remaining rads and also switch off if poss the feed to the UFH. Basically we're trying to separate the system into two halves. NB Do you have a balancing valve in the system...ie a valve/whatever between flow and return that acts as a shunt if/when all the TRVs are closed?

(X) Undo bleed valve on rad 1. It should yield some water which is the water from rad 1 coming out under the pressure in that rad. Not much should come out. It should gradually diminish in volume and flow as the pressure drops.

Once it has stopped open up the lockshield on that rad. Water should start to come out again which is due to the pressure in that leg of the ciurcuit. Quite a bit will come out. It should stop once the pressure has been released.

Once it has stopped I'd re-pressurise and while keeping this bleed valve open the water should start to flow again. Let if flow for quite a while and in an ideal world it will stop and air will come out which is from your airlock and then water. If that happens then close the bleed valve, re-pressurise the system, open up your lockshields and TRVs on rads 1 to 3 and turn on the pump and zone valve so that just these three rads are in the circulating loop. Hopefully they should warm up.

If you don't get to the stage of water-air-water on rad 1 then close the bleed valve and the lock shield. re-pressurise and this time open the TRV on rad 1 and then the bleed valve and see if you get the water-air-water sequence.

If you don't then close off the bleed valve on rad 1, close the TRV and repeat with rad 2 from (X) above.

I think it should work.

 

[TrimTheKing]

I think we need to clear the decks and go back to first principles.

It is a pressurised system.

Looks as if there is an air-lock somehwre stopping three rads from heating up.

How about this for a suggestion?

Turn off the lockshields and TRVs on the 3 rads.

Turn off the TRVs on the remaining rads and also switch off if poss the feed to the UFH. Basically we're trying to separate the system into two halves. NB Do you have a balancing valve in the system...ie a valve/whatever between flow and return that acts as a shunt if/when all the TRVs are closed?

(X) Undo bleed valve on rad 1. It should yield some water which is the water from rad 1 coming out under the pressure in that rad. Not much should come out. It should gradually diminish in volume and flow as the pressure drops.

Once it has stopped open up the lockshield on that rad. Water should start to come out again which is due to the pressure in that leg of the ciurcuit. Quite a bit will come out. It should stop once the pressure has been released.

Once it has stopped I'd re-pressurise and while keeping this bleed valve open the water should start to flow again. Let if flow for quite a while and in an ideal world it will stop and air will come out which is from your airlock and then water. If that happens then close the bleed valve, re-pressurise the system, open up your lockshields and TRVs on rads 1 to 3 and turn on the pump and zone valve so that just these three rads are in the circulating loop. Hopefully they should warm up.

If you don't get to the stage of water-air-water on rad 1 then close the bleed valve and the lock shield. re-pressurise and this time open the TRV on rad 1 and then the bleed valve and see if you get the water-air-water sequence.

If you don't then close off the bleed valve on rad 1, close the TRV and repeat with rad 2 from (X) above.

I think it should work.

Thanks Roger

I will take stock when I get home tomorrow (maybe friday depending how tired I am) and run through this process again as you have documented.

Thanks to all for your help and input, and to those who have PM'd me with help too, it's much appreciated.

 

[Dibs-h]

Mark

Daft question - have you got any pipework higher than the rads?

Teh reason I ask this is last yr I drained & refilled our system (with the boiler in the loft) and we were getting similar probs to yours.

The system used a F&E tank above it. In the end had to get a large'ish stilson around the compression fittings on the flow and return (with the pump switched off) connections on the boiler to release the airlocks.

Regards

Dibs

p.s. I'd follow Roger's advice for now and at least count\discount stuff before deviating.

 

[TrimTheKing]

Thank you all for your help and comments with this.

I spent another 2 hours on it today following Roger's advice to the letter but still no joy, then just as I was about to let fly a final tweak with one of the lockshields (random one) gave a huge gurgle and rush of air and cleared it all out. :shock:

Very happy man now, thank you all.

One more question now, I have replaced an awful lot of the water in the system so I guess I should be adding some more inhibitor. How do I do that???

 

[studders]

I guess I should be adding some more inhibitor. How do I do that???

OK

1) Drain the system...........


:lol: :lol: :lol:

 

[Digit]

If you haven't got the pro gear Mark this is what I do.
Shut off both valves to one rad, doesn't matter which one, then drain some water by cracking one of the joints, this with the bleed nipple undone.
Find a suitable bottle and pour some inhibitor into it, remove the complete bleed valve to obtain a larger hole and squirt the inhibitor in then seal up and top up.
I keep an old bottle that had had gearbox oil in it, the type with a flexible tube as a spout, also one of the liquid soap dispensers should do it.

Roy.

 

[RogerS]

Any vertical rads ..maybe a towel rail...usually have a threaded cap on the top that you can unscrew and it's wide enough to pour stuff in.