Blocked central heating pipe - how to unblock it please.

[daveymoff]

Apologies for an amateur posting on here but I'm trying to get some information before paying out a lot of money.
Sealed system. Biasi boiler 32kw.

I've a blockage in a central heating pipe. I've isolated where the block is, but it's under laminate flooring and floorboards.

Water is flowing into the radiators at the thermostat valve (I'm assuming this is the inlet) and the lockshield valve is clear but the blockage is somewhere further down the pipe. I have tried to unblock it with (please forgive me) a length of wire re-inforced washing line, which fitted into the grey plastic pipe and went for about 9 feet before it became difficult to push in any further (I'm aware of the possibility of puncturing the piping, but it is quite thick and I didn't force it too much).
When the locksheld was removed and I put the pressure up to 2 bar with the mains feeder inlet, there was a small trickle coming out, which I think, adds weight to the fact it is blocked.

So...
any suggestions? Will a chemical additive remove it after a few days? Is hiring a power flush machine advisable (I'm fairly competent at DIY and plumbing generally).

Or are there any other solutions?

Many thanks.

 

[PlumbBobBob]

don't apologise about being an amateur. i think some system cleaner would be a good first thing to try. do you think that at 9 feet you came to an elbow?

 

[daveymoff]

Very possible. I'm convinced it's blocked though, but as I said, any other ideas woould be welcome. I'll go with the additive to start with. Thank you.

 

[shorticus]

Kamco make a product called Hyper-Flush, you can leave it in the system for up to 14 days, they recommend running at full temp. I'm sure there are plenty of other similar products to choose from too

 

[josh0279]

Hi i am having exactly the same problem, i have one radiator in the hallway which doesnt get hot, have taken it off the wall etc and isolated the problem to the return pipe which is blocked but underneath some laminate flooring.

I want to get same cleaner to try and sort the problem but is there any which you would recommend and my main question is how to i add the cleaner to the system? It is a combinaton Vokera boiler system

 

[ecowarm]

Add fernox f3 express like this:
Make sure the system is turned off and allow radiators to cool down. Select a radiator and shut both the wheel-head and lockshield valves. If a thermostatic radiator valve (TRV) is fitted, close it by turning it to the minimum setting.
Having removed the air vent pin using a cloth to absorb any escaping water, screw the Fernox Express injection nozzle into the air vent after cutting to the right diameter to fit tightly. Fit the tube to the adaptor and screw onto the canister. Attach the other end of the tube onto the nozzle in the radiator.
Re-open the wheel-head valve (or TRV) and inject all the Fernox Express by squeezing the trigger for 30 seconds. Then close the wheel-head valve (or TRV), remove the injector nozzle and tighten the air vent pin. Open both radiator valves, turn on the central heating system and let it run for 15 minutes to allow the Expressto disperse around the system.
Not only can the Fernox Express be dispensed directly into the radiator it is also ideal for dosing via system filling loop using the appropriate special adapter supplied with the product. The whole process takes less than two minutes.

 

[WHPES]

Are you sure its a blockage and not an airlock?

Try shutting all your rads down bar the problem one and running the CH (briefly).