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Problems after power flush

View the thread, titled "Problems after power flush" which is posted in UK Plumbers Forums on UK Plumbers Forums.

A

adeltheman

Hi, glad to have found this problem.

I have an issue with our heating system. After a pressure issue was resolved, our engingeer suggested a power flush, which we did.

All fine for 2 months, now it has broken down - the heat exchanger is blocked and the magnetic filter has an inch of crap stuck to it.

Engineer claims he has done all he can and won't come back unless we pay him. It has been suggested there is still chemicals in the system, dislodging more crap - does that sound right?

Our engineer claims the rads - which are less than 7 years old - are rusting inside. No one I have spoken has ever heard of rads failing so soon. The whole system has never suffered from blockages prior to the flush.

Any advice appreciated, thanks.
 
Yes it's unusual but I've seen system full of crud after five or so years, and this was on a sealed system. I've had a similar problem, power flushing doesn't guarantee getting all the crud out. you just have to persevere and keep flushing it out of heat exchangers etc.
 
I did a power flush recently and they had an old suprima, a few weeks later turned out that the hex was nearly completely blocked, they're reasonably smaller than most.
 
It a Gloworm GW30.

If I drained the system whilst opening the inlet valve - would that flush the hex along with everything else?
 
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Whn1 said:
I did a power flush recently and they had an old suprima, a few weeks later turned out that the hex was nearly completely blocked, they're reasonably smaller than most.
Click to expand...

What was the final outcome?
 
Probably not, either needs removing flushing and or renewing. Or iff your lucky some more chemicals. You need a gas safe engineer for this job.
 
if the system wasnt flushed and cleansed on original installation 7 years is quite feasable, and if its open vented then defo can be sludged up, as for chemicals being in the system, possibly but that probaly wouldnt cause it to block up due to just the chemicals. power flushing can loosen muck. is there any circulation on the system at all. i would be tempted to chemically flush it by putting some really strong chemicals in and running for a couple of weeks then flushing out. keep cleaning your filter till you get on top of it!
 
Sealed system - New boiler, 80% new pipe work, and new rads in summer of 2005. Not sure about present circulation as we rent the house out.

There were no issues with blocked hex before the power flush.

If I could clean the hex myself, I would, but I can't.
 
I have seen rads on a sealed system start to corrode after less than 5 years with no chemical treatment! Thing with a powerflush is they pull all the crap through the boiler and if the hex is of small diameter it gets stuck! IMO manually flushing the rads is far better than any powerflush. All that needs to happen now is the system needs draining and the filter needs cleaning, then it needs filling back up and draining again but leave filling loop open until the water starts to run clear, failing that i'd think about disconnecting the heating pipes to the boiler and getting a wet vac on it to try and pull the crap out. Once it has been cleared i'd recommend manually flushing all the rads then leaving a sludge remover in the system for a few days then flush again and leave filling loop open to remove all the sludge removing chemical then fill back up with some inhibitor. BTW the power flush clearly hasn't worked as the whole point is to have a clean system when completed.
 
ah a landlord that explains it, it was probably blocked solid before the flush just trying to get something off the bill.
 
I'm thinking of replacing the hex and having the system empied and refilled. I just need to get things running for a couple of months until our tenents move out, then I can explore other issues.

A hex on ebay is around £65 - is it a complicated job to fit?

Also, the boiler - Glowwrom 30CXi - does it have a secondary hex?
 
adeltheman said:
I'm thinking of replacing the hex and having the system empied and refilled. I just need to get things running for a couple of months until our tenents move out, then I can explore other issues.

A hex on ebay is around £65 - is it a complicated job to fit?

Also, the boiler - Glowwrom 30CXi - does it have a secondary hex?
Click to expand...

Hi,

£65 sounds cheap for a heat exchanger. I would imagine its either a plate heat exchanger (for hot water) that your looking at or a second hand heat exchanger (which if it is second hand I wouldn't touch it!).
 
The system has hot water, not heating - does the heat exchanger supply/provide for both?

The part I was looking at was 2000801831 for Glowworm 30CXi.
 
adeltheman said:
I'm thinking of replacing the hex and having the system empied and refilled. I just need to get things running for a couple of months until our tenents move out, then I can explore other issues.

A hex on ebay is around £65 - is it a complicated job to fit?

Also, the boiler - Glowwrom 30CXi - does it have a secondary hex?
Click to expand...
Are you gas safe registered, you need to be to undertake that job. Even more so if your renting it.
 
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Hang on a minute are you sure the primary hex is blocked?? If it is you won't get heating or hot water, and if the secondary hex is blocked you won't get hot water, the fact you're getting hot water tells me neither of them are blocked and the diverter is probably blocked/stuck. This will need someone to have another look to determine what it actually is thats ausing the htf to not work.
 
Reltub said:
Hang on a minute are you sure the primary hex is blocked?? If it is you won't get heating or hot water, and if the secondary hex is blocked you won't get hot water, the fact you're getting hot water tells me neither of them are blocked and the diverter is probably blocked/stuck. This will need someone to have another look to determine what it actually is thats ausing the htf to not work.
Click to expand...

I'm confused now as well!

All I've been told is the hex in blocked and the heating system has been switched off. There is still hot water though.
 
30Cxi this has got a filter in the side of the left hand block , Not a heat ex problem if boiler is running for hot water, if you can get left side pannel off you will see a brass nut on left hand block have a look at filter may also have some grit ect sticking up diverter valve or, diverter valve motor is not working.
 
Update - in the words of my tenant;

"The previous engineer did all the right things with regards to the power flush and all the other bits but he wouldn't go down the route of replacing the rads just yet, that would be an absolute last resort. He uses a chemical which breaks down the bits in the system and also acts as an inhibitor to stop any corrosion. It doesn't need flushing out the chemical stays in the system for about 5 years. He said if the rads weren't leaking after the power flush then there probably isn't anything wrong with them."

Does this sound about right?
 

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