Central Heating Manifold - Jet Washer

[DerbyBorn]

I had a couple of sluggish radiators. When I was having some building work done I got the plumber to re-pipe one of them whilst the plaster was off the wall. I was out when he did it - he told me that the pipes were clear and that the sluggishness was due to some gunge in the manifold and he poked around when he had the pipe off the manifold. The rad is now perfect.

However, another rad is still sluggish (in the downsatirs bog). The manifold is not very accessable as it is under the upstairs floor and I don't want to risk messing with it and ruining the ceiling.

Question. Would I be taking a risk if I connected my jetwash to the sluggish radiator - with the return valve closed so that I can blast water up the partly blocked flow pipe. I would open a couple of other drain valves to protect the boiler from taking the pressure.

Is is too risky / daft?

The system has always had inhibitor in it and has had a cleaner in a couple of times. I suspect a bit of debris in the inside of the manifold.

[spuorgelgoog]

Yes.

Quoted output pressure of a pressure washer (taken with a large pinch of sa lt) may be over 80 bar.

Your pipes might start popping apart at 10 + bar.

If you want to flush them out use ordinary mains pressure water, with appro priate non-return valve to prevent any possibility of contaminating the mai ns water. Better still, remove the boiler from circuit, use a cheap circula ting pump and a CH system cleaner and desludger then flush through with cle an water then inhibitor.

Owain

[John Rumm]

Imagine this happening to your rads:

I would suggest a mains water flush as per:

[DerbyBorn]

John Rumm wrote in news: [e-mail]:

Blimey

I had tried mains water a couple of years back. I was thinking I needed to perhaps introduce a bit of pulsation to shift whatever it is.

[The Medway Handyman]

Only if a high pressure nozzle is fitted. 80 bar is back pressure when a small nozzle is used.

[Thomas Prufer]

There's gadgets for that, possible something to rent:

Something about mixing air and water, to give the pulsation extra power, and it can use cleaner and inhibitor.

(And I know nothing about it other than that these exist, and the advertising I just googled.)

Thomas Prufer

[DerbyBorn]

DerbyBorn wrote in news:XnsA3E1EB9C13656TrainJPlantntlworldc@81.171.92.222:

Tried mains water again yesterday with another radiator draining to try to create a flow but no success. I had a hose connected to the drain of the radiator (It is a screw operated drain valve in the radiator valve body) with the other end of the radiator closed off. I will repeat the process a few times and then put some fresh additive in as it caused some to get lost.