Blockage or not balanced ?

[trevorbayliss]

My tenants have turned off all the rad valves in the summer and then back on again this autumn. I've been out tonight because the rads are not heating very well upstairs. The hall rad is ok, but 2 bed rads are stone cold and i can feel some heat on the flow pipe, but that's it.

Downstairs the rads are very hot (2 of them). I've tried turning down the downstairs rads to 2 open turns only on the non thermostatic side.

But it has stayed pretty much the same upstairs.

I spoke to my engineer and he says possibly a blockage because the system was very dirty when i got the house (6 yrs ago) and slowly the filter has been pulling out the crude. Tonight i checked the filter and there wasn't that much crude, but still dirty. No error codes and the hot water is working fine.

Im going next week with the idea to drain down and remove the 6 rads in the house and flush them out with a hose pipe. Is this a blockage or a balance issue ?

If its a balance issue would i shut down all rads apart from one at a time and see if they come to life ?

Any tips appreciated

 

[trevorbayliss]

Also is there a blanking nut i can get to block up the rad if i do take it outside to clean out ? It would fit onto the valve part

 

[terryplumb]

Are the TRV pins stuck in the closed position on rads that don't heat ?

 

[ianmcd]

I've tried turning down the downstairs rads to 2 open turns only on the non thermostatic side.

well if you didnt have a balancing problem before, you possibly do now, always close the TRV never the lockshield , unless removing the rad

 

[trevorbayliss]

All the pins have been unstuck if they were as tested them all.

 

[trevorbayliss]

Ive just watched a video by plumber parts. I have a feeling the issue is an air lock.

Will i be able to solve this by closing all the rads down both sides and then just have one open and run the heating for this one rad and use a bleed key to remove any air ?

In his video he is attaching a pipe to the bleed valve area and purging a lot more water out. I would prefer to just do it using a bleed key.

Will i be ok doing it this way ?

 

[terryplumb]

Closing all the rads that currently heat using only their TRV's will achieve the same thing, I.e. consentrate the flow from the pump to those rads that don't heat.
Is the system sealed / pressurised ,or fed from a tank ?

 

[trevorbayliss]

its a sealed system, with a combi.

 

[Madrab]

Unlikely to be an airlock then on a sealed system.

Blanks - It depends on what radiator tails are fitted - if it's normal 15mm tails then a normal 15mm compression stop end male part of the fitting will fit, if it's 3/4" unions then there aren't blanks for them unfortunately, they would need to be bung'd.

Turn off the valves, take the rad off and then open each valve in turn and see if it flows ok into a bucket, any with poor flow indicates a restrictions somewhere, a mains flush may clear it.

 

[terryplumb]

if it's 3/4" unions then there aren't blanks for them unfortunately, they would need to be bung'd

I use male flanged plug 3/4 on union tails. Ok for carrying a rad outside ,and stops dripping crud On the way out.
Not to be used as a plug on a pressurised rad though

 

[Madrab]

I use male flanged plug 3/4 on union tails. Ok for carrying a rad outside ,and stops dripping crud On the way out.
Not to be used as a plug on a pressurised rad though

Yeah tried them once, left too much still in the rad and the lad dropped his end ... 20mins later with a bucket of hot water and soap he was quick enough to get the spots out of their typically light grey carpet, after it soaked through the dust sheet.

I always carry a spare pair of old union lockshields now, just to bang on the ends but I don't suppose the OP would have them.

 

[terryplumb]

Yeah tried them once, left too much still in the rad and the lad dropped his end ... 20mins later with a bucket of hot water and soap he was quick enough to get the spots out of their typically light grey carpet, after it soaked through the dust sheet.

I always carry a spare pair of old union lockshields now, just to bang on the ends but I don't suppose the OP would have them.

---

 

[oldbutnotdead]

Got to be worth checking the lockshields haven't been closed (it's amazing how many of these manage to close themselves cos the tenants swear blind they haven't touched them).
After that yes try all off and one on. The airlock sketch- that method of removing the bleed valve (on modern rads it's dead easy) is very good for shifting big bubbles trapped in high spots on pipe runs- there isn't enough flow just using the bleed valve. Less messy on pressurised systems (no faffing with bungs on the f & e tank), don't forget to top up the inhibitor when you've finished

 

[trevorbayliss]

Been today to flush manually most of the rads. Lots of sludge in there.

Looking at 15 mins per rad to get them clean. I used a rubber hammer to also lightly bang on the rads.

All back on and a cleaner will now run for the next 2 weeks.