cold rad

[067256]

10mm microbore drops down to the rad in question. Microbore behind 'dot and dab' plasterboard.
Could i force mains water up the return pipe via the bleed valve and 'hope' the blockage shifts?

 

[PaulRB]

067256
At the start of my troubles I took off the rad and attached a hose to the flow valve, connected to the outside tap ( but any mains tap will do ). Then I opened the valve and opened the outside tap. The mains pressure should force water into the pipework and hopefully shift the blockage.
I then repeated the process for the return valve.
BUT only run the mains for 5-10 seconds or it will back-fill the F + E tank ( you will know this because water will start coming out of the overflow!!! )
Also, it can be fiddly trying to attach a hose to the valves but worth persevering.
It might clear the blockage.
Good luck.

 

[fuzzy]

Pump switched off.
Closed both valves on rad and removed the rad in question. Opened flow valve and get a good flow of water.
Open lockshield valve and only a trickle, there is nothing wrong with the valve as i have actually tried it on another rad when i fitted a TRV.
I'm just convinced now that it is a blockage.

sounds like it mate, maybe force mains pressure back up

 

[PlumbingBud]

Microbore is well known for being soft and getting squashed easily. It is also prone to blockage being of narrow bore.
I wonder if there is a squashed bit behind the dot and dab?

Its like a garden hose being kinked. Water may well flow through, but will be unable to reach top flow rate.

 

[fuzzy]

if its worked before and no works been done its unliekly to have become kinked

 

[067256]

Ok, so today i have traced as much of the pipework as possible by taking up floorboards etc....
i cannot find any kinks. squashed bits. It goes 22mm down to 15mm down again to 10mm for about the last 2 metres.
I have taken off the rad in question and connected a washing machine hose between the flow and return...opened both valves, turned on heating briefly to check and now i have a good flow and the washing machine pipe is getting hot!!!
Why dont i get this when i connect the rad back up???????????????????????????????????????????????

 

[PlumbBobBob]

maybe a restriction in the radiator? take it outside and put your garden hose on it and flush it out

 

[fuzzy]

Ok, so today i have traced as much of the pipework as possible by taking up floorboards etc....
i cannot find any kinks. squashed bits. It goes 22mm down to 15mm down again to 10mm for about the last 2 metres.
I have taken off the rad in question and connected a washing machine hose between the flow and return...opened both valves, turned on heating briefly to check and now i have a good flow and the washing machine pipe is getting hot!!!
Why dont i get this when i connect the rad back up???????????????????????????????????????????????

take rad outside and flush it out

 

[067256]

Its a new rad...flushed out still and all ok.

 

[fuzzy]

must be greater resistance, the system needs balancing

when rad off did you open both valves for split second to check they both run well?