Blockages in 10mm plastic central heating pipes

[JohnJa]

Our house was built in 2007 and we are the second family to live here - moving in in 2017. The central heating has been working fine - although the gas boiler is perhaps nearing the end of its life. But the boiler is not our current issue.


Last winter two of the radiators did not heat up and another radiator heats up very slowly. Hot water from the boiler for heating goes to a manifold and there is a manifold for the return. From the manifolds there are 10mm plastic pipes to and from each radiator.


On each problem radiator I have identified whether the blockage is on the flow or return by turning off the valves each end and unscrewing the pushfit elbows to see whether water escapes or not. I bought a very long length of flexible curtain wire and my attempt to unblock each radiator has been:
1. turn off the rad valve and lockshield
2. undo the elbow at the offending end of the radiator
3. pull off the pushfit elbow
4. push in as long a length of flexible curtain wire as I can


This has resulted in a little "crud" coming out of the radiator flow (or return) pipe, but only a dribble of water. Reconnecting the pushfit elbow and opening the rad valve and lockshield again tells me that I haven't solved the problem. The radiator still doesn't get hot.


Does anyone have any other DIY suggestions, or is it time to call in a professional to flush the pipes?


Thank you in advance for any help.

 

[snowhead]

Wet vac, or even normal vac considering how little water is likely to come out.

Have you tried the curtain wire down from the manifold end?

 

[JohnJa]

Wet vac, or even normal vac considering how little water is likely to come out.

Have you tried the curtain wire down from the manifold end?

I don't understand what "Wet vac" or "normal vac" is.

I have thought of trying the curtain wire from the manifold end, but firstly the plastic pipes exiting the manifold are not labelled (perhaps the installer should have done that) and secondly won't there be a big flood of water from the manifold if I disconnect one of the plastic pipes?

I guess that I could work out which pipe is which at the manifold by turning on the radiators one by one and seeing which gets hot. That's fine on the flow side, but might be more difficult on the return side.

 

[ShaunCorbs]

Would drain down and check all the ports on the manifold you well see which one when you remove the pipe

 

[JohnJa]

Would drain down and check all the ports on the manifold you well see which one when you remove the pipe

The boiler is due for an annual service in November. So I will ask the engineer to drain the system and check the manifold ports if I don't get our problem solved by then.

 

[fowlerboi]

Have done it before with a pressure test pump. Keep pumping a section of pipe up until the blockage flys out the other end.

That obviously means disconnecting the manifold which means draining the system down. It also means a lot of mess unless managed properly and a risk assesment of other damages to the system needs to be done.

Just get a plumber in....

 

[jh2254]

Problems with small bore pipe and an old central heating system

Use your magnet to investigate extent of blockage, depending on what you find- cut out and replace that section of pipe

www.plumbersforums.net

Been there and done that! See my thread.
Dont call in a plumber yet!
What I used was not flexible curtain wire but stronger thin guage wire I bought from a DIY store. Similar thickness as the wire on a coat hanger. I would try this and see how far you can push it up the pipe to remove the crud.
Good luck and let us know how you get on.