Confusing heating

[sxturbo]

I have been trying to fix my heating for a little while now. Back in February my heating was working spot on, since it has been idle for the summer I am now experiencing issues with cold radiators.

After balancing them numerous times I had home serve out 3 times who haven't done anything more than I have even though we are paying for central heating cover, which is pretty darn useless as there not interested in sorting anything unless the issue stares them in the face.

Anyway I digress

Today I tried flushing the system. Both my rads in the lounge have hose tails on, so I plugged the hose pipe on the rad that doesn't work, and the drain on the one that does work. Have locked off all the radiators individually and all seemed to return ok.

Except for the hot feed to the radiator that doesn't work. This did seem to be blocked as couldn't here the water going through this pipe and the drain outside came to a standstill.

So I'm pretty certain this pipe is blocked, where it goes to I have no idea though.

We then took the rad off and gave that a good flush, some black sludge came out but I have seen much much worse in my dad's house.

Any way refilled the system, bled the air out the system, put heating on, downstairs rad are all boiling hot except for the one that doesn't work in the lounge, none of the upstairs rads worked.

So balanced the rads, now the rad in the bathroom works, and the rad in the baby's room half works.

The master bedroom feed pipe is burning to touch, but the rad is stone cold.

The 2nd rad in the lounge does not work.

Switched off all the lock Shields to the radiators down stairs, leaving the upstairs and the rad in the lounge that doesn't work, on. This kept making the boiler shutdown due to over hea ting, and the return feed to the boiler was stone cold, none of the rads that were on worked.

Reset all the lock Shields on all the rads, and now back to square one.

I know there is clearly a blocked pipe, how I trace this I do not know. It's seems to only affect the radiator in the main bedroom, and the 2nd rad in the lounge.

The rad in the main bedroom is the closest to the boiler, the 2nd rad in the lounge was an add on at some stage.

It seems odd that the rad not workin in the lounge is affecting the rad upstairs.

The boiler was making some funky noises while just the upstairs radiators were on.

 

[John D v2.0]

can't quite understand your post but I got the gist. can you flush it through the other way? checked the valve isn't stuck?

 

[sxturbo]

Valves aren't stuck.

Basically I'm saying that I have 2 radiators that seem to refuse to work.

One of the 2 radiators that doesn't work both the fed pipe and the return are stone cold. The other rad that doesn't work has a hot feed pipe.

When locking off all the radiators except for the 2 that don work, the boiler kept going into shutdown mode.

However, all the rads filled up with water nicely, and all the rads have pressure in them even the ones that don't work, when bleeding the rads that don't work the water squirts out at a nice pressure and suggests there is flow.

Flushed the system both ways.

 

[alan333]

You don't say what type of system you have, but if it's any help - on our vented system with the small tank in the loft - I paid attention while the Scottish Gas guy cured ours.
With the heating off - He took the valve off the radiator and opened the valve into a bucket to check if there was flow. Repeated with the other valve. One was much worse than the other. Now he removed the valve from the pipe and used a garden sprayer, a bit like this...
https://www.gardenlines.co.uk/shop/...MItNflm87t1wIVFGYbCh2Bhw2XEAQYByABEgJf7fD_BwE
...and pumped it up with air (not water), connected it to the pipe and released the sharp burst of pressurised air back up the pipe, then allowed the lumps/dirt to flow back down into the bucket. After a couple of bursts the flow was much better.
Bear in mind on my system the burst of air simply ended up in the small (only partially filled) tank in the loft, I don't know if you can achieve the same somehow on a pressurised system. And also bear in mind the radiator will obviously drain down while the valves are disconnected from it.

 

[Doggit]

I suspect you're right that it's a blocked pipe, so these need flushing next. You should be able to work out where the pipes go, and if you go round all of the rads as the heating comes on, you should be able to spot the sequence. So you need to take off the rads either side of the blocked pipe, put a hose with one end attached to the kitchen tap, and the other end on one of the valves, and a small piece of hose on the other valve that goes into a bucket. Someone turns on the tap, and that should push any debris through the pipe, and into the bucket. Obviously, the valves have to be fully open, and you need to knock up a couple of adaptors that has a copper tail for the hose (with a circlip) and and a connector to go where the radiator was (you'll need to make two up, one for either end) and then it's just a case of moving from feed to feed, and then return to return, and flush the sludge out as you go.

What a lot of people don't realise, is that if you've got sludge in the rads, it's very likely in the pipes as well, so they need doing at the same time. I can see that the garden spray is trying to do the same job, and it'll be easier to use, but it may not have the same pressure as a kitchen tap, nor the flow.

 

[sxturbo]

Thanks for your reply. The garden tap I fitted a couple of years ago and is tee'd from the kitchen tap, so I assume the pressure is the same.

Someone has fitted tap valves to the main offending radiator, on both the return and feed https://www.screwfix.com/p/isolatin...gclsrc=aw.ds&dclid=CPPgoJjX7tcCFe6G7QodW54Iuw

They have also used stainless steel hose to connect the copper pipes. We did note the isolator valve is not full bore and may not be helping the situation.

I also assume that they have taken the return from the upstairs rads to add this radiator. And so the blocked pipe is stifling the return.

We did try flushing this one pipe but to no avail.

I will have to take up all the floor boards and fin where the pipe runs.

Thanks

 

[Doggit]

If they've got flexi pipes and isolators, then these could be the problem rather than a blocked pipe. But although the isolators aren't full bore, they should still let enough flow through.

As the pipe is a downward one, you may be able to cheat, and get someone to open up the filling loop taps at the same time that you take off the isolating valves, but if you empty too much water out of the system, then you'd need to add some more inhibitor in afterwards - this assumes that you've got a pressurised system of course.

 

[sxturbo]

Thanks. Yes we have a pressurised system.

At the moment I have not put inhibitor back in as know I will be draining it again very soon.

Thanks for your help

 

[Hot&Cold]

Someone has fitted tap valves to the main offending radiator, on both the return and feed https://www.screwfix.com/p/isolatin...gclsrc=aw.ds&dclid=CPPgoJjX7tcCFe6G7QodW54Iuw

They have also used stainless steel hose to connect the copper pipes. We did note the isolator valve is not full bore and may not be helping the situation.

Thanks for the new information,seems your faulty radiator pipework has been compromised above floor level,Feck knows what is happening below the floor level.
The isolation valves & steel hose have to be exchanged for copper pipe & radiator/lockshield valves,then see if it improves circulation.
If still faulty the offending radiator pipework needs investigating and possible re run from a known good supply.

Its a process of elimination

 

[sxturbo]

Had a plumber come round. Done the same things i've done, came to the same conclusion.

Can't get anything sorted till the new year. Looked into my homeserve policy further and my central heating system is covered, albeit they don't cover power flushing the system, although the plumber agreed that seeing as me putting mains pressure through the system didn't clear the system having a power flush will be of no use.

So homeserve are coming out Tuesday, I'm not really holding out much hope for them to be honest, I'm sure they will come up with some sort of excuse to not fix the system.

 

[abbadon]

Any joy?

 

[sxturbo]

Not yet.

The pipes are all over the place with very little sense as to why they travel where they do. I think I know roughly where the fault lies. And after some arguing homeserve are coming out tomorrow to locate the issue, and they are going to then send a plumber round to fix it.

What's confusing is that some of the radiators in the upstairs loop work and not others, yet when the downstairs rads are shut off the return to the boiler doesn't get hot, yet the radiators do.

 

[sxturbo]

Just thought I give an update on this.

Today me and my dad changed the stainless Flexi hoses and 4 of the small bore isolators (there is 2 under the floor boards that seem impossible to get to, and there is another 2 which feed the not working rad, but these are hidden behind a stud wall which is tiles from floor to ceiling, and I can't be arsed to change these just yet)

This seems to now be feeding heat to all radiators bar the 2nd rad in the lounge that stopped working. This now has hot water flow, but not through the rad or the return.

This may improve with balancing however.

It also seems the old pipework for the back boiler has been used, which is fine, but I would have thought the upstairs rad would be tee'd from the 28mm pipe before they go down stairs but this is not the case. They are all fed with 15mm pipe from downstairs to up, which places the rad closest to the boiler he furthest from the feed..

Anyway I have also fitted a fernox tf1 omega filter, and some f5 cleaner, I will empty the filter 2-3 times this week and then drain the fernox f5 and refill with fernox inhibitor the one they recommend for there filter.

Fingers crossed it's all sorted.