New radiator - hot top warm bottom

[iamlucky]

Hi guys,

I hope you are all well.

Moved into our first house in March. I had a new radiator installed in our bedroom (replaced a decoration type one which never warmed up the room). The downstairs feed pipework were terrible so I had a plumber replace them - not copper but with flexibly tubing - don't know the material. The existing radiators were retained. The feed pipework upstairs were not touched at all, bar the one for the bedroom.

The new radiator used to warm up perfectly but I had to call out the plumber again as I noticed a leak on the bathroom radiator. System drained down, leak fixed and system filled back up (about 2 months ago). Even after that, the bedroom radiator used to work perfectly.

However, I noticed that ever since then a lot of air gets drawn into the system, so I have to bleed the radiators upstairs and re-pressurize about once a week.

Earlier this week, the radiator didn't warm up at all - stone cold. The feed pipe to the upstairs radiators was gurgling, as well as the radiator first in line. I turned one of downstairs radiators off at the TRV and lockshield, and lo and behold the radiator now gets hot (but not very) at the top and warm at the bottom. Feed pipe steaming hot, return pipe warm. No gurgling from feed pipe to upstairs, as well as that first in line radiator. All the other radiators steaming hot - no cold spots.

I don't think it's sludge because it's a new radiator. I think there might be an air lock.

I called the plumber again and he was stumped - which was a bit shocking considering his experience.

Any ideas what the problem could be and how I can solve it?

Thanks for your help in advance guys.

Have a Merry Christmas and a Happy New Year 🙂

 

[SimonG]

You either have a leak or an issue with your boiler. You shouldnt have to constantly repressurise.

 

[iamlucky]

You either have a leak or an issue with your boiler. You shouldnt have to constantly repressurise.

I don't constantly repressurize (sorry - I might have confused people); only when I have had to bleed the system a few times of air and a lot of air comes out. Can the pump be failing?

I switched another rad off, put the boiler on and it warms up a bit more, as well as the return pipe - something must be holding the flow back?

 

[southcoastboile]

Partial blockage in pipe work, or system may need balancing. Or air locked.

 

[village idiot]

The fact you heard gurgling, and the fact you have to bleed constantly, means you definately have an air lock somewhere. That radiator may be the highest, hence the need to bleed it constantly.
Why was your experienced plumber stumped?

 

[iamlucky]

The fact you heard gurgling, and the fact you have to bleed constantly, means you definately have an air lock somewhere. That radiator may be the highest, hence the need to bleed it constantly.
Why was your experienced plumber stumped?

Our conversation went something like this:
Me: blah blah blah blah
Plumber: Does your pressure drop?
Me: Noooooo
Plumber:......... I'm stumped mate.

Sounds like he couldn't be bothered to come around. I'm also suspecting that inhibitor wasn't added to the system whilst the system was being filled backup and that it wasn't done properly or in sequence. So there must be some corrosion taking place but it is a slow process so it can't produce that much air so quickly.

Bleed the radiator again. Lits of air came out again. Put the heating on, and it warms up a bit more and so does the return pipe.

Had a look at a video on how to remove an air lock but it looks like you need balls of steel, which i don't.

Can i not just drain the system and do it back up again?

 

[sheff paul]

Make sure the rad isn't piped up with 10mm plastic if its a big rad the top will be hot ,but bottom cold,if its 15mm to the rad,it will be undersized further along feeding too many rads on 15mm