Flushing a vented central heating system
Discussion
Dear Wise ones
We have a flat that is currently empty. We are about to re-market it for letting but have an issue with the central heating system. It's a traditional (vented?) header tank system rather than a combi.
Symptoms: Boiler cuts in and out at very short intervals (maybe 1 minute or so). Radiators warm (not hot) at the top but cold at the bottom. Never really warm up to an acceptable level.
A plumber has been to see it this morning and is happy that the boiler and pump are functioning ok. They diagnosed the problem as a build up of crud, maybe even a partial blockage in the system inhibiting water flow. That seems like a reasonable conclusion particularly after seeing how black the water was when I tried bleeding one of the radiators.
I suppose firstly, would you generally agree that the symptoms fit the diagnosis?
The plumber that was there this morning has steered us away from a power flush. He was concerned that the system may be fragile to start pumping high pressure through. I think this may in part be a concern becuase the this is a first floor flat and the flat below is unoccupied 6 months of the year. The heating system is probably about 30 years old. If any leaks were propagated they could be undiscovered for months. He has suggested trying a magnacleanse service initially. I hadn't heard of these but they sound like a good idea. He has offered us a price of around £400 to do a professional magnacleanse flush, fit a permanent magnaclean system, do a boiler service and a 1 year gas safety certification. Around 5 hours work I'm told.
Does this sound ok or am I getting my pants pulled down?
We have a flat that is currently empty. We are about to re-market it for letting but have an issue with the central heating system. It's a traditional (vented?) header tank system rather than a combi.
Symptoms: Boiler cuts in and out at very short intervals (maybe 1 minute or so). Radiators warm (not hot) at the top but cold at the bottom. Never really warm up to an acceptable level.
A plumber has been to see it this morning and is happy that the boiler and pump are functioning ok. They diagnosed the problem as a build up of crud, maybe even a partial blockage in the system inhibiting water flow. That seems like a reasonable conclusion particularly after seeing how black the water was when I tried bleeding one of the radiators.
I suppose firstly, would you generally agree that the symptoms fit the diagnosis?
The plumber that was there this morning has steered us away from a power flush. He was concerned that the system may be fragile to start pumping high pressure through. I think this may in part be a concern becuase the this is a first floor flat and the flat below is unoccupied 6 months of the year. The heating system is probably about 30 years old. If any leaks were propagated they could be undiscovered for months. He has suggested trying a magnacleanse service initially. I hadn't heard of these but they sound like a good idea. He has offered us a price of around £400 to do a professional magnacleanse flush, fit a permanent magnaclean system, do a boiler service and a 1 year gas safety certification. Around 5 hours work I'm told.
Does this sound ok or am I getting my pants pulled down?
If you can't do it yourself then no, the price is good.
If you're capable of doing it yourself then yes it is too much!
The diagnosis sounds correct, the cure could be easy.
If you have a long length of hose you can drain the system yourself (remember to stop the header tank from refilling by tying up the float) and then using a hose and pipe with a fitting that fits into your radiators you can flush each radiator in turn loosening up the crap and letting it flow through the hose to the drain.
Were it me, I'd do it myself, I can't afford £500. If your day is important to you then you might want to pay it.
If you're capable of doing it yourself then yes it is too much!
The diagnosis sounds correct, the cure could be easy.
If you have a long length of hose you can drain the system yourself (remember to stop the header tank from refilling by tying up the float) and then using a hose and pipe with a fitting that fits into your radiators you can flush each radiator in turn loosening up the crap and letting it flow through the hose to the drain.
Were it me, I'd do it myself, I can't afford £500. If your day is important to you then you might want to pay it.
Pothole said:
Cheers. Great link. freecar said:
If you can't do it yourself then no, the price is good.
If you're capable of doing it yourself then yes it is too much!
The diagnosis sounds correct, the cure could be easy.
If you have a long length of hose you can drain the system yourself (remember to stop the header tank from refilling by tying up the float) and then using a hose and pipe with a fitting that fits into your radiators you can flush each radiator in turn loosening up the crap and letting it flow through the hose to the drain.
Were it me, I'd do it myself, I can't afford £500. If your day is important to you then you might want to pay it.
Cheers. I'm not sure whether its so much 'capable' as 'willing'. I would be prepared to try a system flush using mains water if this was generally considered effective. The plumber that saw it was of the opinion that the crud was far too thick for this to be effective. I suppose he would say that though!If you're capable of doing it yourself then yes it is too much!
The diagnosis sounds correct, the cure could be easy.
If you have a long length of hose you can drain the system yourself (remember to stop the header tank from refilling by tying up the float) and then using a hose and pipe with a fitting that fits into your radiators you can flush each radiator in turn loosening up the crap and letting it flow through the hose to the drain.
Were it me, I'd do it myself, I can't afford £500. If your day is important to you then you might want to pay it.
I suppose what it boils down to, is that I'm happy to pay the bill if it sorts the system out. He seems adamant that it will but obviously couldn't guarantee it.
Ask him what the difference between a Magna-Cleanse flush and a Powerflush?
A Powerflush doesn't actually use high pressure, just high flow.
Its a large resevoir with a directional pump on it. It isn't pressurised, you can use it with the cap off the machine.
I'd agree with him about fragile systems, I've been a bit cautious of doing flushes on properties with pipes buried in the screed.
A cheaper solution (not as effective) is to drain the system and refil it with a sludge remover, like Sentinel X400 and run the heating for a few weeks.
It will eventually break down and mobilize the sludge deposits and you can drain and refil a few times until the water is noticeably cleaner. Couple this with a Magnetic filter fitted permanently connected to the system can only have positive effects.
Still, you'll never get it as clean as you would with a machine.
A Powerflush doesn't actually use high pressure, just high flow.
Its a large resevoir with a directional pump on it. It isn't pressurised, you can use it with the cap off the machine.
I'd agree with him about fragile systems, I've been a bit cautious of doing flushes on properties with pipes buried in the screed.
A cheaper solution (not as effective) is to drain the system and refil it with a sludge remover, like Sentinel X400 and run the heating for a few weeks.
It will eventually break down and mobilize the sludge deposits and you can drain and refil a few times until the water is noticeably cleaner. Couple this with a Magnetic filter fitted permanently connected to the system can only have positive effects.
Still, you'll never get it as clean as you would with a machine.
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