Help Diagnosing plumbing issue - lukewarm radiators

[Aco]

Hi,

Would be really grateful if someone could advise us as best they can regarding our radiator issues.

The previous house owner installed 3 new radiators in the kitchen but they barely heat up. If 10 is max power, I'd say we achieve 3.

We have British Gas Homecare so have had them out on numerous ocassions with no success. They have tried re-balancing the system to direct more flow downstairs and fitting a new pump to the boiler but this made little difference. They are not sure of the exact issue but feel it would be best if we do a powerflush.

We decided to contact a local plumbing company to get their opinion and they feel a powerflush is not needed. They advised that it is likely that the new radiators do not have a direct feed from the boiler (all the pipework is hidden in the walls), but that they are probably using a feed from elsewhere and that this is not sufficient to heat them up.

We agreed on a solution - to install new pipework from the boiler to the 3 radiators in the kitchen. Anyway, the company sent someone out and he advised he was going to look for a blockage rather than fit new pipework. He couldn't locate a blockage, but he found a network of pipes on the first floor that was feeding the kitchen radiators (on drops) and the pipe feeding the downstairs radiators was a very narrow pipe going into a wider pipe. He re-routed the wider pipe to another wider pipe hoping this would fix the problem.

It seemed mildly better for an hour or so then all the downstairs radiators (except the hallway) were stone cold. I contacted the plumbing company and they advised we have 2 options - take up the bathroom tiles so they can see where the pipes go (??) or run new pipework from the boiler to the kitchen radiators (our original agreement)!

Sorry this is so lengthy. If anyone can offer any insight it would be much appreciated.

Thanks

Aco

 

[Razor900]

Turn off all the upstairs rads and see what happens

 

[Aco]

Hi Razor,

Thanks for your reply.

I've turned all the upstairs radiators off and now the main kitchen radiator is booming hot, the other two are about 3 out of 10, heatwise. The other two I believe may be on a different circuit (being fed from the bathroom upstairs), whereas the main kitchen radiator is the one that is fed from the network of pipes they located and adjusted yesterday.

There is no change to the living room radiator though, stone cold. Strangely enough we'd never had a problem with this radiator before so this is something newly created from the work that was done yesterday.

I'm not sure if this will help, but I bought a thermal camera yesterday to locate the network of pipes as it is all in the walls. It should arrive tomorrow so hoping if I can at least work out where the pipes are and potentially if there's a blockage....(?)

Also, what do I do now? Shall I turn the rads upstairs back on but not as fully as before?

thanks

Aco

 

[Doggit]

How far are you opening up the rads. Obviously the TRV should be fully open, and the locksheld about a half turn. If you turn the hot kitchen rad off, what then happens to the other 2.

He re-routed the wider pipe to another wider pipe hoping this would fix the problem

This was a daft thing to do, and "hoping" it would work, shows he didn't actually know what he was doing. Do you know why there was a narrow pipe, that then went into a wider pipe (I assume 15mm the going in to 22mm).

Try turning the rads on one at a time, and see when the system falls over.

 

[Newboy]

It may seem like a daft idea but ......

Turn the central heating off (thermostat down to min) and DHW on (cylinder stat up a little until the boiler kicks in) - is there any heat in the bathroom rad and the three 'newer' rads?

 

[Agile]

Is that ANY rad which cannot get hot with all the others turned off?

If not then I would expect that balancing is a possibility.

But it does need to be done very carefully and normally with no lockshield open more that one full turn.

A very good starting point is to open all lockshields just 1/2 turns and in many cases they all heat up well and it can be left like that.

Amusing how BG's diagnosis always includes a power flush ( @ £800 ) as a starting point.

Last week I went to someone whose BG man had given up unless a power flush was done.

It tool me less than an hour to clean the boiler filter and the Mag filter to restore the heating and hot water.

Very annoyingly she has not paid me and worse is not coming to my party!

Tony

 

[dpsservices]

Hi Razor,

Thanks for your reply.

I've turned all the upstairs radiators off and now the main kitchen radiator is booming hot, the other two are about 3 out of 10, heatwise. The other two I believe may be on a different circuit (being fed from the bathroom upstairs), whereas the main kitchen radiator is the one that is fed from the network of pipes they located and adjusted yesterday.

There is no change to the living room radiator though, stone cold. Strangely enough we'd never had a problem with this radiator before so this is something newly created from the work that was done yesterday.

I'm not sure if this will help, but I bought a thermal camera yesterday to locate the network of pipes as it is all in the walls. It should arrive tomorrow so hoping if I can at least work out where the pipes are and potentially if there's a blockage....(?)

Also, what do I do now? Shall I turn the rads upstairs back on but not as fully as before?

thanks

Aco

What camera did you buy and what's it like ? As I'm having same issues but with micro bore regards david

 

[dilalio]

OP: test one rad at a time, with ALL others closed.

Do this with CH only.

As you test each rad, identify which pipe gets hot first: TRV or lockshield. Note this on each rad.

Then check if the TRVs for each rad are bi-directional and/or if any of the rads have baffles in them, meaning that flow and return 'have' to be on specific sides.

If any of the rads do not get fully hot during this test, then you have incorrect piping issues, as assumed above. If the non-functioning rads are grouped, then this will indicate where that piping fault is likely to be.

If you can get full heat into each one, individually, then careful balancing, pump speed setting and sealing up the system if OV could be a solution, before lifting floors.

 

[DaveHerns]

Very annoyingly she has not paid me and worse is not coming to me party!

Special occasion?

 

[Aco]

Thanks for all your responses, really appreciated.

I will try to go through all the suggestions this afternoon and post an update this evening.

Regards

Aco

 

[Aco]

Hi Doggit,

Interesting you ask how far we are opening the kitchen rads, for the main kitchen radiator the TRV is fully open with lockshield half a turn. Actually, just noticed the other two kitchen radiators are missing their TRV, so perhaps this could be part of the problem...? That they are actually not fully open?

The other two are now gaining 1 out of 10 heatwise. Switching the main radiator off doesn't seem to affect the output of these two.

With regards to them 'hoping it would work'...we've had a fair few people in (mostly British Gas) who have drawn a blank and everything seems to be largely guesswork.

As I understand, the narrow pipe was part of the old network of pipes on our 1st floor and the larger pipe was seemingly fitted into it when the previous owner installed the new rads in the kitchen. (I hope this is making sense!)

I'll try turning the rads on one by one tonight to see where the system falls over.
--------------
Agile - yes, the 2 kitchen radiators do not get hot with all others turned off (either 0 out of 10 or 1 out of 10 heatwise).

BG have been frustrating to say the least - 8 visits, 3 different engineers, over 10 hours total - none of them can diagnose the problem yet feel a powerflush will be beneficial?! At twice the cost of a local plumber. Plus, I can't see how the brand new radiators can have sludge issues when all other (old) radiators are working perfectly. Doesn't make much sense to me but this is my first home and I am new to all this.
----------------
dpsservices - I bought the Flir One for IOS (170 pounds) which attaches to an iphone/ipad. I'm pretty impressed so far - within minutes I can see the network of pipes hidden in my walls! Nobody could ever work out where the pipes on the ground floor were so now at least we know. It traced pipework under laminate flooring as well, but unable to see through the bathroom floor tiles.
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newboy/dilalio - will have a look at your suggestions this evening and revert back.
-----------------
thanks

Aco

 

[Doggit]

Sorry Aco, but you still haven't mentioned the pipe sizes yet, and I wonder why the rad installer didn't redo the wider pipes; I wonder if the wider pipes were part f the original system, and they cut across into them. But if you're right that the narrow pipes were part of the original system, then a) why switch to a larger pipe, and b) is the narrow pipe adequate to supply the new rads.

I'm surprised that 2 of the new rads don't have TRVS, but it's not desperate. Just make sure one side is fully open (unless you already have), and leave the other side at half turn, and then see if they heat up.

Your next exercise may take a couple of days, but you need to run round the house, and check the pipes as they get warm, and try and work out the heating pattern of the system. It's a shame that the other company didn't do the initial agreement to reroute the pipes to the boiler, as that may well have solved the problem, so is it worth just getting that done, and then checking for any problems. What is the pump speed set to, and have they upped it to overcome the increased resistance for the new rads.

You do seem to be having a rough time of it. BG suggesting a powerflush just implies they're not sure what's going on, so they may be good at new installations, but not problem solving, and the other company didn't follow you're agreed instructions, so you've been left to turn to us.

 

[Aco]

Hi Doggit,

Sorry, I don't know exactly what the pipe sizes were under the floor unfortunately. I only saw them briefly when talking to the plumber. The narrow pipe was very narrow and and the plastic pipe it was attached to seemed much wider.

My explanation before was confusing so I'll try to re-summarise. There was a network of pipes under the floor on the 1st floor (nursery room). The main kitchen radiator is fed on a drop from these pipes in the nursery. The other two radiators have a different routing (which I located on Saturday with my thermal camera). The narrow pipe was part of the original system and was connected by the previous owners to a wider new plastic pipe and fed on a drop to the kitchen. The plumber advised it may be advisable to connect the plastic pipe to a wider pipe in the original system so that there is more flow and therefore better output for the main kitchen radiator. So to confirm, we are no longer using the narrow pipe.

Following the advice on this thread, we turned off the upstairs rads and the main kitchen radiator is kicking out decent heat (even after turning the others back on). So it does appear that switching to the wider pipe indeed fixed this radiator.

Sorry, they do actually have TRV's, but it looks like they are missing a connector so we have never been able to use the TRV's. I have posted some photos for you to see which may be easier. Just to confirm, to make sure it is fully open, do I turn the black nut on the left hand side anti-clockwise until it goes no further?

The plumber is coming back this afternoon to discuss what further work needs to be done, so I will ask him about pump speed.

We have had a bit of a rough time unfortunately, this house has been a bit of a nightmare - two extensions were done and it has transpired that the plumbing was done by the previous owners husband, who was a builder.

With regards to BG, yes I agree. We have found them useful for straightforward issues, such as boiler needing a replacement part but as soon as anything is not straightforward, they seem to be completely out of their depth.

Thanks again.

Aco

 

[Newboy]

to make sure it is fully open, do I turn the black nut on the left hand side anti-clockwise until it goes no further

Don't turn anything on the left-hand side, depress the pin to check that it moves in out out freely (only a few millimetres). Fully open the lock-shield on the right-hand side by turning anti-clockwise.

 

[Doggit]

Newboys right in telling you to just test the LH (trv minus head) to make sure it's open, but you want to adjust the lockshield on the right hand, and start it at half a turn, and then open it up in quarter turns till you get the heat output you want. It almost sounds as though you may have had a microbore system, and there could well have been a blockage in it; and if that's the case, then it's actually possible that BG's powerflush may have cleared things - just an expensive way of doing things. If the rads are now up to the required temp, then don't worry about the pump speed.