Radiators not coming on - Powerflush necessary or a rip-off?

Doc_N

Actually, I don't think it's really microbore. Pretty much standard mid-1980s tubing.

Alex1983

A power flush machine is unlikely to clear a complete blockage and I would say even more unlikely to clear blocked manifolds.

Geoff1963

you can hear there's air in the system

I don't think power flushing would fix that.

Doc_N

Appreciating all the help and advice, guys. Essentially, this is a sudden failure of the heating side of a gas fired central heating system, with the boiler still working normally and the hot water side still working normally.

The pump was replaced, because that was the initial diagnosis, but that made no difference - still no heat to the radiators (none at all - not even a trace).

The 'engineer' has taken the head off the Honeywell motorised valve and claims it's working normally. The valve, if that's the right term, underneath is free, so he says he's been able to turn it to 'on' for the heating. There's another, different looking motorised valve at the point where the pipework goes into the HW cylinder, but that seems to have nothing to do with the CH.

His theory is that there must be an air blockage somewhere, and that a power flush is needed to clear it. My theory is that a power flush will achieve nothing and leave the fault still unidentified. But, as I've said, this is not my field and I rely very much on the experts.

Meanwhile, the emergency insurer has now said the power wash isn't covered and washed their hands of the matter!

keith969

First flat I bought had problems with air locks in the CH. It required draining down and carefully filling with one particular radiator's bleed valve open to get rid of the air in the system. Nothing to do with blockages.

Le_Kirk

If the diverter/3-port valve is able to be turned by hand (or by using the manual over-ride), fire up the boiler by setting the time switch to call for heat, set the thermostat above the ambient temperature, make sure boiler is firing. Feel the pipe that feeds the diverter/3-port valve. Is it hot. Operate the diverter valve manually, is the outlet pipe hot? If that works the problem is with the control of the diverter valve. I don't know what type of controller you have but is it the type where you can advance the heating/hot water? If so, it might be worth sitting near the diverter valve and pressing the advance button for hot water - what happens to diverter valve; then ask for heating - what happens to diverter valve?

Doc_N

In case it's of any interest, the problem's now resolved.

The power flush seemed pointless, possibly even problematic, and wasn't covered by the home emergency insurer (RSA) anyway. RSA proved to be particularly useless, because having turned down the power flush they then washed their hands of the matter entirely and decided it was our problem - not theirs. So much for their stated policy of looking after vulnerable customers; this one was in his 90s and needed the central heating for a medical condition.

Anyway, I got an independent contractor to take a look, and he resolved the problem with a little thought and rather more knowledge of heating systems that the RSA contractor had. It turned out to be a blocked cold feed pipe in the loft, which he had to cut out - solidly blocked with crud from the radiators over a number of years.

£120 all-in for 3.5 hours work, inhibitor and a couple of new valves. Pretty reasonable, I thought, but a shame that the contractor RSA called out couldn't have dealt with it properly.

firefox1956

Glad you got sorted with a good local independent.
You were right to be suspicious of the good old power flush scam.

Wookey

Doc_N wrote: »

In case it's of any interest, the problem's now resolved.

The power flush seemed pointless, possibly even problematic, and wasn't covered by the home emergency insurer (RSA) anyway. RSA proved to be particularly useless, because having turned down the power flush they then washed their hands of the matter entirely and decided it was our problem - not theirs. So much for their stated policy of looking after vulnerable customers; this one was in his 90s and needed the central heating for a medical condition.

Anyway, I got an independent contractor to take a look, and he resolved the problem with a little thought and rather more knowledge of heating systems that the RSA contractor had. It turned out to be a blocked cold feed pipe in the loft, which he had to cut out - solidly blocked with crud from the radiators over a number of years.

£120 all-in for 3.5 hours work, inhibitor and a couple of new valves. Pretty reasonable, I thought, but a shame that the contractor RSA called out couldn't have dealt with it properly.

I came across this very same problem about 25 years ago, the first guy had obviously just checked there was water in the tank and assumed there was water in the system, i made the same mistake initially too that time but on digging into it more it soon became apparent that the water wasn't getting into the system so either airlock or blockage, i was lucky at that time in that i could disassemble the whole cold feed intact from valve to coil and clear the blockage outside with an outside tap and a bit of wire as a rod. Lol sometimes you gotta look further than your nose.

Doc_N

CleverCaz wrote: »

Try a powder flush, it’s a new technology that’s better than power flushing. They specialise in blocked or hard to clean systems like microbore, blocked heat exchangers and plastic pipes. I had a very similar issue with not enough flow in the system. Four heating engineers and a lot of money later, was told to replace all the pipework. Got powder flush out and it got sorted within a day.

Thanks, but see post 18 above - the problem was solved without a power flush (which would have been utterly useless, as would a powder flush).

Powder Flush (which I see is a newish franchise business looking for franchisees) looks very much like yet another opportunity to part customers from a lot of their money.