Air in all radiators every morning, HELP!

[jeanne]

Hi

Last two days have woken up to cold radiators because of air in the system. When I bleed a rad, they all heat up again.

Bit of background:

System is Baxi Bermuda back boiler. Two rather small cold water tanks in cupboards about 6ft above hot water tank.

Had a new shower pump and auto air vent fitted in July by reputable company (thought charge was excessive at £787).Afterwards, shower worked fine but radiators not very hot.

BGas serviced boiler two weeks ago. Engineer turned up water temperature (to 75 deg). Rads now very hot, shower now too hot, difficult to adjust. Turned water down to 70 deg. This was the last service before I cancelled agreement (because too expensive and each year covers less and less).

Three days ago found bit of air in shower room rad. Bled it. Next day, air in all rads, all cold. Same today. Auto air vent has been throwing out a bit of water by the look of it.

Am a complete novice with plumbing, but have been badly ripped off a few times and want to try to avoid it again.

Before I call a plumber, just wondered if anyone can help suggest a reason and remedy?

Is the problem likely to be related to any of the recent work carried out?

Anyone know a good plumber in central London? :-)

Sincere thanks for any help/advice.

[Simon Avery]

Hello jeanne

I suspect overpumping, and as it's easy to test for worth checking first.

CH pump - turn speed selector down. As well as messing with the thermostat, your BG Guy may have twiddled the speed also. Most houses don't need more than "I" - but in all cases, the pump should be set to the lowest speed THAT STILL HEATS ALL RADIATORS.

If I'm right, would explain water being pushed out the air valve - which if I'm not, would be the next suspect.

Why do you think so many of us in here prefer to struggle and learn this particular skill?

[Roger Mills]

Difficult to comment without a few more details. Where exactly is this auto air vent - is it in the primary circuit - which includes the boiler, radiators and indirect coil in the hot water cylinder - or is it in the feed to the shower?

How is the domestic hot water temperature - as opposed to the boiler flow temperature going to the radiators - controlled? Is there a thermostat fixed to the hot water cylinder? (not one incorporated into an immersion heater, if any)

Roger

[John Laird]

I rebalanced all 12 radiators in my house recently. It had obviously never been done properly as I ended with many valves screwed down to about 1/2 open (at most) and some left fully open. They all have TRVs fitted.

However, when I experimented with nudging the pump down from 3 to 2 (one or two radiators are a bit whooshy noisy as a result) this could set up some amazing banging and clanging noises. I think the pump was struggling against some of the TRVs. It sounded like one rad trying to shake itself loose of its fittings. The pump is back at 3.

[BillR]

Good grief!

Good move.

Its rumoured that plumbers there can make >£100k /year now ...

First of all, never use a real email address on Usenet because it will get intolerable amounts of spam thereafter.. A Baxi Bermuda back boiler must be getting quite long in the tooth now. I wonder if the increase in the temp by B Gas has found a weakness somewhere that is now leaking.

[Grunff]

Nonsense! I use my real email address with pride. Not doing so is giving into spammers.

Even then, only a small percentage of my spam is Usenet derived (

[Bob Smith]

How can NOT using your email address be giving it to spammers?

Another reason not to use your real address: I only know 2 people who were emailed the swen virus: my spam account, and a guy at work. Both addresses were used in newsgroups. The swen virus looks in different types of files to find email addresses, and will post fake messages to newsgroups. As far as I can see, there is nothing to stop it reading newsgroups to trawl for email addresses.

Bob

[jeanne]

Hi Roger

Auto air vent is situated between the hot water cylinder and the "mid position valve" (above the central heating pump).

The temperature controller ("Drayton") is on the hot water cylinder and adjusted with a screwdriver. This is the only hot water storage.

Thanks,

Jeanne

[Grunff]

Because if spammers didn't spam, you *would* use your real email address. By *not* using it, you are allowing spammers to influence your behaviour, ergo you are giving in to them.

It's like allowing burglars to influence your behaviour by fitting locks to your doors.

First time I've heard of swen (or any other virus) trawling Usenet for addresses.

[Bob Smith]

So if you don't fit locks, burglars won't be interested in your house? If you don't give your address, you can't get spammed.

It trawls files on your hard drive, and posts to usenet. All I am saying is they may not have noticed it trawling usenet for addresses (a combination of the 2 already documented actions) when they disasembled it.

Bob

[Roger Mills]

Ok - that's useful - the air vent is clearly in the primary circuit. I can think of 3 possible reasons for your problem - in no particular order of likeliness:

• The air vent could be faulty - and could be drawing air IN [Is it possible to disable it, and see whether that makes any difference?]

• Your system could be "pumping over" - and drawing air in through the header tank [Is there a constant flow of water through the vent pipe into the primary header tank when the system is running?]

• It may not be air at all - it may be hydrogen, caused by corrosion in the radiators if the system doesn't have inhibitor in it [When you bleed a radiator, try sticking a match to the "air" which comes out. Does it burn?]

You mentioned earlier that when the boiler temperature was turned up, the shower became too hot. But, the shower is presumably fed from your stored hot water tank? From what you say, you have a cylinder stat and a mid-position valve. If so, it is possible to control the temperature of the stored hot water so that it is cooler than the water going to the radiators. [The boiler flow temperature should be about 80 degC, but the domestic hot water only 55-60 degC]. This should enable you to have hot radiators without the shower being excessively hot - but you *must* sort the air problem first.

Roger

[jeanne]

Hi Simon

Thank you for your suggestions. Forgive my ignorance, but how do I turn the speed down? The pump is GRUNDFOS UPS 15-50x18 with a large "screw-head" at the front with an up arrow on the right and a down arrow on the left. Is this the speed selector? It doesn't have any settings on it, but is currently "aligned" at "twenty to two" :-) or it would be if it was a clock!

OK, point taken :-)

[jeanne]

Good grief!

Good move.

Its rumoured that plumbers there can make >£100k /year now ...

Hi Bill

Thanks for your message. I'm obviously in the wrong job!

I appreciate your comment about spam, you are absolutely right, this email address got slaughtered before, so I don't really use it now. It has an auto-spam filter on it now so spam gets deleted before it reaches me (365 in the 7 days!). Unfortunately, I signed in via Google Groups and it didn't give me the option to edit my address.

The Baxi is a bit old, but never had any problems with it (hope I'm not tempting fate). Have had a good look around the whole system for leaks, can't spot any ... yet :-)

[John Laird]

That's a cover for the motor spindle I think (which you can turn by hand/screwdriver if it's stuck). The speed adjustment is a plastic rotary dial on the side of the pump. It will show 1, 2 or 3 in a window to the front. (Well, it does on mine, which is a slightly different model. But the 15-50 designation means adjustable from 15 to 50 somethings. On the front, is there a sticker showing wattage or flow rate at the 3 settings ?)

[Michael Mcneil]

Glad using British grammar now. Sounded you write telegramme.

Get extra hotmail address. Get signed in that. Not use again. Also sign in Mailgate -see posts sooner.

Must learn snip posts too.

[Simon Avery]

Hello jeanne

Nono - that's the bleed screw (undo it slightly only if you've got air stuck in the pump, ie, it's making a hell of a noise).

No, the speed selector is usually (at least on my grundfos, and the one before it) on the side cover where the wire enters. (On mine, to the left of that shiny screw)

It could be yours doesn't have one of course, in which case my suggestion is completely wrong. :)

[PoP]

That may be the case now. However I was talking to the principal of the local college at a networking meeting a few weeks ago, and I commented that it was a pity that the college doesn't offer plumbing courses. His reply was interesting.

Basically he said that in the first place they didn't have the real estate to host plumbing courses on the campus, which seems a fair enough reason not to be hosting the courses - if there isn't the physical room then it's a no-go area. But he went on to say that within the academic circles which he frequents (and let's face it, as principal he's bound to be in contact with other principals and leading figures at other colleges where these courses are run) it was well known that the UK is training far too many plumbers at the moment

- if you try and book on a plumbing course anywhere you'll possibly have a wait of a year or two.

And he reckoned that in 3-4 years time the market will be saturated with qualified plumbers looking for work.

Add to that the situation where the EU is throwing open the doors to anyone who wants to come in to work - and plumbing is one of those trades which is internationally transferrable - and I wouldn't mind betting that plumbing is going to get a whole lot more competitive in the next few years. Rates will tumble, etc.

The IT industry has been through something like this over the last couple of years, it's just starting to pick up again at the moment but it probably isn't likely the high figures will be earnt again for quite some time, if ever.

So in my estimation the plumbers who are earning the big bucks right now need to make sure they don't over-commit themselves on mortgages and so on, just in case the dark clouds do gather over their industry. No good looking to the Labour government for help - President Blair has just gone on record as welcoming the shipping of jobs to foreign lands:

that you can necessarily ship plumbing to the other side of the world like you could IT and call centre work, but if you take into account the immigration policy of the current government we'll be just as happy allowing their plumbers coming over here.

PoP

[Toby]

I think this is widely expected, so we are currently paying the high rates now while the sun still shines for plumbers. Southern European trades are happily working in Switzerland, Austria etc. The new eastern European EU entrants will be more likely to work in the UK. I think now is a great time to set up agency to cater for them, maybe even produce an English/Polish plumbing phrasebook. Will the European equivalents of Corgi and ACS accreditation be acceptable in the UK? I guess EU legislation would encourage it.

[Mike Tomlinson]

In article , Grunff writes

[jeanne]

Many thanks, I found it and have turned it down. There is a "whooshing" noise coming from the system, so - as we already know - there is a lot of air in it. Guess I'll end up calling in a plumber :-(