Steaming header tank and asbestos

[RichardMaid]

Hi all

Thanks again for everyone who helped sort out my original problem of a stuck return valve and I now have a near perfect central heating system.

I have a problem if any of the skilled guys (and gals) can answer, and I would be very very grateful. To be brief, I have a Victorian 3 bedroomed house with a gravity fed system and a glow-worm boiler (about 1983 - yes it is old). Firstly, the plumber won't service it as he says it is on a list from Corgi as having asbestos in. Where can I find anyone to service it?? I'm down in Maidstone?

The other issue - He looked in the loft and I was shocked to see water dripping from the beams etc. The header tank was steaming, but the water in it was luke warm to hottish. It has no lid, but also an overflow pipe hanging over the top, not in the side. He said firstly my boiler temperature was up too high, then that the system must be sludged up, as one of the radiators is always half empty of air near the loft - bathroom (soon after bleeding). Yet he also said all gravity fed systems give air in a radiator anyway.

I have had it jet flushed in the last year, but he says it can't have been done properly, yet my radiators are all hot (bar that one). My 'magnafilter' was sludged up and water in the pot itself brown when I emptied it yesterday, but then I hadn't emptied it for a while. I have thrown a black bin liner and a towel over the header tank to stop the condensation. Should/can I get a lid fitted (with that pipe hanging over it) and does the header tank always have warm to hotish water in it anyway?? My breath steams up there anyway! When ever I start the system it immediately start filling the header tank too (you can hear it and it runs for a while). Sorry for the long message, but I am reluctant to have another jet flush at £400-500.

Can anyone bear to advise me?? Richard

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[JohnD]

turn down the pump speed, see if that reduces the pumping over. Water is not supposed to come out of the vent pipe unless something is wrong. You can buy a plastic lid and cut a hole to fit round the vent pipe.

please post photos of the pipework around the pump, cylinder and boiler. especially the 15mm feed and expansion pipe (from the small loft tank) and the 22mm vent pipe (hangs over that tank), and where they are in relation to the pump.

who did the powerflush? do you consider them a reputable company?

do you know what (?any?) inhibitor was added to the system when refilling after the flush?

search on "pumping over" for similar troubles

 

[RichardMaid]

Many thanks John

I was hoping you may say nothing was majorly wrong. The pump has 3 speeds and it's set on 2 whihc has worked fine (very quiet pump). I don't know about the reputation of the power flush people, but I didn't pay the earth. You'd be right, he put in scoops of a powder at the end of the flush, is that what you mean? I will gladly send pictures from the airing cupboard when I get in tomorrow evening. The pump is on the floor below the large boiler, in the airing cupboard in a back bedroom directly below the tanks in the loft. I can't think I have had this problem before, as I have never noticed mildew on the beams etc. I have to say the radiators are all hot bar that one in the bathroom next to the airing cupboard which always has air in.


Richard

 

[heatingman]

Clearly you do have a problem with your heating system if its steaming and pumping over, but I think you also have a ventilation issue with your loft. Or is the tank confined to a cupboard.

 

[simond]

You may want to consider altering the expansion tank to a combined cold feed and vent. The boiler should be fitted as standard with an overheat stat for this to be recommended.

 

[bengasman]

if your magnaclean was sludged up and the water is brown, i sincerely doubt they did a good job flushing it.
powder could well have been neutralising crystals, only you don't stick them in at the end, but before the rinsing which for me usually takes a good couple of hours before it is really clean.
provided the pipework is essentially done right, overpumping is often another sign of blockage.

 

[RichardMaid]

Thanks to all so far on this one. It wasn't peanuts Ben, I would say mid range, but I take your point. As far as the sludge issue is concerned, the radiators are very hot which made me question the sludge issue. The plumber as you read thinks the problem is sludge as he replaced a stuck return valve last year. Although he has suggested checking another one. To be honest the jet flushing was a year ago, so the exact point of the neutralising powder was at some point near the end, but not sure exactly when. The water in the magnafilter was certainly brown and I guess this shouldn't be after good power flushing?

 

[bengasman]

part of what i qualify as a good powerflushing job is the thorough rinsing which gets rid of the dirt that you loosen up.
another equally important part is to make sure all acid is gone.
a third important part and again really essential is adding sufficient quality inhibitor to make sure the process does not start again.
although powerflushing is no rocket science and you can learn pretty much all there is to know about it in one day, it is amazing how many people do it without understanding how to go about.
the bottom line is: the purpose of the exercise is not to hook up a pump and let it run, but to clean each and every heat exchanger i.e. primary hex, secondary if present, cylinder if present, and all rads. open vent system also needs tank and f&e cleaning.
if you are sure you have done this, you can be pretty sure you will have automatically cleared all blockages to and from in the process.

oh, don't take the peanut thing personally, it is just a signature.

 

[RichardMaid]

Thanks Ben

No probs with the peanuts, I know what your saying. I agree with all you say, it's just I simply do not know if this plumber did a good job or not. I go back to the point that my radiators are hot, which would imply it's not blacked?? but why is it venting up into the expansion tank? After having it jet flushed earlier in the year, it did not improve but another company specialising in old bolilers identified immediatley it had a stuck return valve and replaced this and the change was dramatic. Now the winter has arrived I have hot radiators and a steaming header tank. This latter company argue it can only be a sludged up system (maybe the configuration of pipes - but it's worked for 20 years I presume) and your point about was it jet flushed properly. Anyway I have rung them this morning and they are coming to assess it all on the 8th and I will turn the pump right down til then.

Richard

 

[Rico99]

Rich,

Can you just clear up one point for us.

Everyone seems to have jumped to the conclusion that your heating is "pumping over" into the f&e cistern but you last comment has made me query it.

Is it "pumping over" ie water coming from the vent pipe hanging over the f&e.

or

Normal expansion coming up from the feed pipe to the boiler.

If it is the latter that is normal, the water in the f&e will be hot and as there is no lid it will let the steam rise upto your rafters and condense.

Rico

 

[RichardMaid]

Thanks Rico

I need to get home and check, and I'm no expert, but there is a pipe hanging over the top which appears to disappear out under the roof to outside. But obviously there is another pipe you're saying connected to the system and I need to check this. There is a ballcock with an over flow pipe in the side and a pipe coming in from the bottom. When the system starts I can hear the expansion tank filling and it goes on and on when I listen. It isn't silent and the water in the bottom of the tank quickly becomes warm. Now I'm sitting in my office (lunch break of course) and that's how I have to remember it. My earlier point is about this being normal, and I just need a lid with a hole for the pipe over it to direct the steam away? However, there is still air in the bathroom radiator despite bleeding. I need to check your point more thoroughly tonight.


Richard

 

[RichardMaid]

Hi all

Had a chance to look properly - and yes it is pumping over. When the boiler starts water pours gently from the vent pipe over the expansion tank. I have turned down the boiler heat and the pump and leaving it off as muhc as possible. Two radiators have air in upstairs and all are very hot elsewhere. I am more and more thinking this was a bad jet flush and the system is sludged. Plumbers in on the 8th.


Richard