To power flush or not to power flush?

[ik9000]

One for the plumbers:

We've got a radiator (upstairs bathroom) that keeps oscillating between working normally and barely getting warm - for several days at a time. Rad is brand new, valves are new and confirmed working. Plumber thinks there may be some kind of blockage in a pipe that is building up, releasing, build up again etc. He's not sure where though. The old rad worked fine for most of its life then started doing the same after the valves were changed to thermostatic ones hence we got the rad changed. We've also had the valves swapped again just to make sure it's not those either.

I'm not sure what our options are and what the best course of action is.

Should we just get the system power flushed, and is that the right thing to do? Am I right in understanding it's just shoving water through at high pressure? Any risks to that eg bursting joints, resulting leaks etc? Are there any alternate steps we could/should take?

 

[ik9000]

Thanks everyone, really useful. System has inhibitor in it already. All the upstairs rads (bar one) are new, it's just downstairs still to be changed. The one we kept is working fine so we probably won't move it as we've just finished decorating that room and the new carpets fitted in there. With all the furniture back in we can't really get good access to it, not enough to remove it and get it outside easily anyway.

The blockage doesn't seem to be in the rad itself. So far as the plumber could tell it was under the floor, possibly under the bath itself. There's a donkey show of missing floorboards and pipe spaghetti under there to make you weep. I'll see if plumber can recommend a cleaning solution to throw in it for the weekend and christmas period as I doubt he'll have availability this side of the holidays given timing and the ever increasing restrictions etc.

 

[ik9000]

dumb question but how do I tell if I have a filter already? What should I be looking for, and where in the house would it be? By the boiler or in the loft etc? We're on a gravity system with tanks in the loft. Boiler in GF kitchen.