Power Flush Required??

[JohnD]

small magnet to detect a blockage of black sediment. though I have my doubts as you seem to have a lot of new pipe there, and sediment takes a while to settle and harden.

p.s. if you can label what those various pipes (seem to) do it would help.

 

[Doallyn]

small magnet to detect a blockage of black sediment. though I have my doubts as you seem to have a lot of new pipe there, and sediment takes a while to settle and harden.

the pipework under the floorboards and round the boiler is all old though - would a sticking magnet confirm a blockage or just a sediment build up?

 

[hi-spec plumbing heating]

you can connect a powerflusher where you like.
we connect them on pumps,rads,cylinders etc.

 

[JohnD]

would a sticking magnet confirm a blockage or just a sediment build up?

I've only found it attracted to a blocked Tee. In a run of pipe, the water flow will tend to carry sediment along is suspension, so it will tend to settle in a quiet corner (also at the bottom of rads). In a blockage it can go hard and dense.

I am not a plumber

 

[brentwoodheating]

Air must be the chief suspect. Have you tried running it on just CH and just HW? Have you tried back filling it?

 

[JohnD]

looking at your picture, I can see the 3-way valve, with the feed from the pump going into the bottom, and one of the exits going down through the floor, presumably to feed the rads, although it looks like it might be 28mm, which is odd. I can't see the pipe going into the bottom of the pump in the picture. Presumably there is one, and it goes to the boiler. Is the boiler downstairs from the cylinder?

the three-port valve seems to be at the top of a bunch of pipes. If it had air in it, how would the air escape? Is that the vent teed off just to the left on the cylinder feed?

the return from the bottom of the cylinder also looks odd. It appears to have a T from the F&E joining it from above; but then it seems to go two ways. One of them should go off to the boiler, but where does the other one come from? Is it the radiators return? Provided the gate-valve is open, any air at this point could escape up to the F&E, but it would tend not to have air in it because air would rise to the top of the coil. How would it escape from here?

what is that white-painted pipe beside the F&E wheel-head gate valve? Is it the cold feed to the cylinder? Or to the cold bath taps?

When the pump is running, does any water flow out of the vent into the F&E?

 

[Doallyn]

Air must be the chief suspect. Have you tried running it on just CH and just HW? Have you tried back filling it?

Backfilling?? i've tried just CH and HW on their own with no joy which makes me suspect a problem between the pump and boiler

 

[Doallyn]

looking at your picture, I can see the 3-way valve, with the feed from the pump going into the bottom, and one of the exits going down through the floor, presumably to feed the rads, although it looks like it might be 28mm, which is odd. I can't see the pipe going into the bottom of the pump in the picture. Presumably there is one, and it goes to the boiler. Is the boiler downstairs from the cylinder?

the three-port valve seems to be at the top of a bunch of pipes. If it had air in it, how would the air escape? Is that the vent teed off just to the left on the cylinder feed?

the return from the bottom of the cylinder also looks odd. It appears to have a T from the F&E joining it from above; but then it seems to go two ways. One of them should go off to the boiler, but where does the other one come from? Is it the radiators return? Provided the gate-valve is open, any air at this point could escape up to the F&E, but it would tend not to have air in it because air would rise to the top of the coil. How would it escape from here?

what is that white-painted pipe beside the F&E wheel-head gate valve? Is it the cold feed to the cylinder? Or to the cold bath taps?

When the pump is running, does any water flow out of the vent into the F&E?

there is a vent tee'd off from the pipe going into the cylinder from the pump

the pipe going into the pump from the boiler is at the bottom it comes up from the floor boards then has the overflow pipe coming off it up to the loft then goes up to the pump

the return does split as it comes out of the cylinder - this is where the cold feed is - it then splits and i believe one is the radiator return and the other heads down to the boiler!

i haven't seen any water coming into the F&E but i can check this, also i read about see-sawing and if any air is being sucked in??

 

[JohnD]

there is a vent tee'd off from the pipe going into the cylinder from the pump

the pipe going into the pump from the boiler is at the bottom it comes up from the floor boards then has the overflow pipe coming off it up to the loft then goes up to the pump

Do you mean there is a vent, and an overflow pipe, and a feed/expansion pipe, all going to the loft? Total of three?

Do any of then joint together?

Are any of then turned off with a valve?

It is usual to have one 15mm Feed & Expansion; and one 22mm Vent.

Can you put up a pic of the F&E in the loft?

 

[gas_man_gaz]

Hi guys, if you've been following my screwed up heating system - this is the next chapter

bascially its an open vent system with a new cylinder, pump, 3port valve and programmer recently installed - everything is installed and working in terms of the individual items - the boiler fires, the pump goes round, everything is bled BUT there is no hot water circulating from teh boiler (which gets hot) to the pump!

the pipes out of the boilder are hot but at the pump its cold! - anyway, having struggled to figure all this out we got British Gas to come in for their one price fixes all deal, so this guy turns up - firstly says that the pipework is wrong and the cold feed needs to be moved to the pipe at the back (i wasn't there for that - cos that meant putting the cold feed into the pipe going into the pump from the boiler - err not quite right i think)

so next day he returns and now says that they don't need to do that but that there is a blockage and we need a powerflush that isn't covered, and also cos our boiler is so old they can't cover that and can't fix the problem - see you later bye!

so now i'm back to where i started - in a cold house! if there is a blockage between the boiler and the pump i can't see that it just suddenly formed when we drained the system to change the cylinder?? is there anyway of detecting this blockage, which must be in the pipework under the floor boards and is the power flush the only way to fix this - we couldn't say find the blockage, replace that piece of pipework and then treat the system chemically afterwards?!?
its all so frustrating!!!!

why did ya have the 3port - cylinder and clock replaced?

as for bg, they wont repair a boiler/sys wen it has had 3rd party involvement as it can make fault findin a right pain as they dont no wat the other plumbers have done to try n get it workin!

and the cold feed norm t's in between the expansion pipe and the pump!!

 

[Doallyn]

thanks for all the help and comments people - finally got it sorted last night with the help of my plumber mate who actually took the time to look at the problem and work on it for a bit

turned out to be an airlock and some draining, filling, venting and turning the pump on then off then on etc.. finally shifted it and the heat started going round the system

took some time but it didn't need a power flush or reconfiguring of the pipework! so much for BG and people who make a quick diagnosis without really looking at the problem!

thanks to everyone though on here - been a great help!
I now know so much about heating systems!! more than i wanted!

Cheers
Alex