Has our plumber put us in danger?

[vexation]

Alerted to a problem by the outside overflow from my H&E tank, I discovered that during a recent visit my plumber had deliberately raised the F&E to submerge the expansion pipe. The water in the tank was really hot when I inspected it.

The motive I think was to cure air getting into the system. The plumbers had just swapped in a new condensing boiler (open vent system) and there was constant gurgling and swishing that days of bleeding and head-scratching just wouldn't cure. The pump was set to its lowest speed but on stopping and starting you could still hear it overpumping (?) into the F&E so I suspect this was the inspiration for the "system modification".

Submerging the expansion pipe seems a bit non-standard to me, and I don't think it has cured the air getting into the system either. Having recently heard of fatalities through scalding water dropping down from attics I'm not sure if our system is even safe to run.

As for the air (?) in the system, the pipework is in the right order with the cold feed just under the pump inlet - and expansion just under that. The system was power flushed and filled with corrosion inhibitor and wasn't impossible to bleed before the new boiler was fitted. None of the new pipework appears to have leaks - hence everyone is clutching at straws (evidently).

 

[seco services]

if it is constantly running yes it is unsafe as them plastic tank will only hold hot water for a certain time and they go like jelly.

was it powerflushed properly as pumping over indicates bad pipe arrangement or pump speed to high, blockage etc.

he needs to come back and sort the problem.

has he done any pipework near the pump ?
was it a problem before he came ?
was the system reliable before ?

 

[vexation]

if it is constantly running yes it is unsafe as them plastic tank will only hold hot water for a certain time and they go like jelly.

was it powerflushed properly as pumping over indicates bad pipe arrangement or pump speed to high, blockage etc.

The flow in the H&E isn't constant.

Both HW & CH paths seem to pull in air but both seem very effective apart from that so I don't think it's a blockage. The powerflush took all day and half the night so I think it was done thoroughly. Pump speed is on lowest setting (which seems adequate to get to all rads)

he needs to come back and sort the problem.

has he done any pipework near the pump ?
was it a problem before he came ?
was the system reliable before ?

The pump was changed at the same time as the boiler and the cold feed and expansion were swapped because they were in the wrong order before. Ironically, before these changes the system didn't gulp air like it does now.

 

[heatingman]

theres a fault with the plumbing/pipework either existing on new, the installer is incompetant and has bodged it

 

[seco services]

have you any pics of the pipework ?

powerflush took alday and half the night. that tells me something about them straight away.

so it was them that have ballsed up.

theirs not much they can balls up around the pump. not rocket science.

as said its a pipework arrangement problem.

 

[vexation]

theres a fault with the plumbing/pipework either existing on new, the installer is incompetant and has bodged it

"Bodged" is a bit strong isn't it. What would they say if I told them that

have you any pics of the pipework ?

Maybe in a bit.

powerflush took alday and half the night. that tells me something about them straight away.

Quite a big house though, I don't think it really tells us much.

so it was them that have ballsed up.

theirs not much they can balls up around the pump. not rocket science.

as said its a pipework arrangement problem.

But it all looks text-book around the pump/F&E - plenty of head, right order, flow direction etc.

One issue though is bypass: There's a manual bypass valve as well as just one rad without a thermostatic valve. The plumber started off saying there was no need for the bypass, but since has opened it up a bit. Playing open and shut with it, the nature of the sounds in the system change dramatically. If air is circulating (it always seems highly entrained in the water - more like foam) then opening the bypass fully seems to settle it down.

 

[seco services]

"Bodged" is a bit strong isn't it. What would they say if I told them that





if i was you i would be telling them abit more.

what valves do you have after the pump 1 x 3 port or 2 x 2 port ?

 

[ChrisR]

YOu're confuddling your pipes - and so is your plumber.
Yer tiZ:

//www.diynot.com/forums/viewtopic.php?p=891831#891831

The fat pipe over the top is called the VENT
The small one to the bottom of the tank is the Feed and expansion pipe.
Water expands into the tank, not much up the vent.

 

[vexation]

Here's the layout around the pump. It's a 3-port valve. I couldn't get a photo of it all in so I sketched the valve and the indirect coil in HW cylinder.



I didn't get to see which pipe was churning - I was enlisted to start/stop the pump while plumber was up in the loft. I could just hear it swooshing up and down. If it was just the feed that was pulling in/pushing out then why would air get in? There's a whole head of water above the point where the feed joins the tank.

I spoke to a mate who had similar problems with his open vent system. Given that the circulating water has inertia, and the bigger the system, the more inertia, I can't help thinking that the pump needs some sort of soft start/soft stop facility. Maybe I ougth to develop one

 

[heatingman]

make/model of new boiler?

 

[doitall]

Looking at that pic "Bodged" is definitely not strong enough.

Cowboy, would be getting closer.

Whats the rest look like.

 

[vexation]

heatingman: the new boiler is a Glow Worm Flexicom 30hx. The old one was a Glow Worm Ultimate 80FF

Looking at that pic "Bodged" is definitely not strong enough.

Cowboy, would be getting closer.

Whats the rest look like.

I think the original installation is mostly mostly to blame for the scrappy appearance, although I can sort of see how the new work could have been neater. Nothing else is really visible. The pipework in the loft looks quite sensible and is properly lagged - apart from where the engineer jacked-up the F&E tank on four plastic bottles.






What else in the pipework could be the cause of air getting back in the system - I'm afraid I've got to say that dunking the vent does seem to have settled everything down now, which suggests to me that the dynamics of the pump and nearby pipework are to blame (nobody liked my idea of a soft start/stop pump controller then?).

The point where the rads return to the boiler is unknown as it all happens under large sheets of flooring chipboard. There's a fairly long run of about 12m between the pump and boiler and a total of 16 rads.

 

[DP]

Really depends what you asked your plumber to do. If only a boiler change, then perhaps he has done that adequately. But if it comes to 'sorting' the problems on existing as well for the same price, that then is a different ballgame.

Looking at the picture, plumbing 'seems' to be correct. Jacking up the F+E cistern may be to 'correct' plumbing run on the F+E pipe which has resulted in expansion pipe dipping into the water.

 

[Shift]

Well jacking up the f+e tank with plastic bottles tells me one thing"bodger" . Hope you haven't paid him yet.

 

[tonybhoy]

Well jacking up the f+e tank with plastic bottles tells me one thing"bodger" . Hope you haven't paid him yet.

Mibbies the guy was only trying something temporarily to see if it worked....