Cold water storage tank giving hot water

[thebtr]

Any help with the following appreciated.

Yesterday a gas fire engineer removed a CH radiator & in doing so allowed a large amount of air into my open vented CH system. I've managed to bleed most of the air from the system, though noted that when I ran the cold water supply that the water from the storage tank was very hot. Why might this happen?

The CH pump is on the return side of the system & I've noted that during normal operation it appears to be drawing a small amount of air into the system (I can't find any air separator). Similarly, two automated bleed valves appear to be work normally most of the time only to occasionally 'suck' air into the system. Can they both be faulty? The boiler itself is of the condensing type which even on the warmest of days produces clouds of vapour. I've never had this type before so don't know how much moisture is the norm, though it appears excessive to me. Is it possible that the heat exchanger is cracked?

I'm thinking it might be easier to change the boiler & convert the system to a sealed, pressured system using the existing pipework (one plumber thought the pipe runs across the loft to the expansion tank were too long for the bore of pipe & suggested that the only effective remedy would be to replace the whole pipe runs from the boiler to the loft & immersion tanks). Might a change of boiler be a practicable solution &, if so, any thoughts as to what type of boiler I should look at?

btr

 

[corgiman]

This is way too complicated to sort out through a forum I think mate really need professional help but i will address some of your points

Steam from a condensing boiler even when hot outside.... This is perfectly normal as while the boiler is condensing it will emit water vapour through the flue.

If the pump is on the return and pulling air into the system then the system is not up to manufacturers recommendations and the pump MUST be relocated to stop this imeadiatley. Converting to a sealed system will do this

As for the run of the expansion pipe being too long this is total and absolute rubbish as this pipe is a safety valve and as long as it is permanently open then that will do... I would question that plumbers competency I would

as for the hot water in the the cold water storage tank this could be a myriad of things so get a decent person in to sort it

 

[thebtr]

Unfortunately, getting professional advice isn't as easy as it would appear, so thanks for your suggestions.

I'm thinking the water in the tank got hot perhaps because the guy racked up the thermostat on the immersion tank (I noted it had been moved) & had the immersion on all day - cold water storage is otherwise normal.

As to the pump being on the return, the plumber said that this wasn't that unusual in older systems. Is that correct as I can't understand why a plumber would have installed a pump where they should not? Will lowering the CH pump speed reduce air getting into the system? As for the automatic air bleed valves, am I right in thinking that if they take in air they must be faulty?

Oh for the pleasures of a sealed system.

BTR

 

[oilman]

Pumps used to be installed on the return, I think the reasoning was it was cooler for the pump, but I might be wrong. Turning the pump speed down might help.

Suggest you replace the immersion thermostat. It might be ok, but they are so cheap its a reasonable way to spend some money. Make sure you get the type that is "non-self resetting" and don't be sold ANY that is self resetting. They are not the best engineered piece of kit, and they ought to be replaced every couple of years if used a lot, cost about 5p/week.

Automatic air valves do have problems esp in hard water areas, they should only be a few pounds each, so repalcing them is cheaper than cleaning them. Get the type with a self closing service valve if you haven't already got them, then you can just unscrew the old body and screw in the new.

 

[thebtr]

Thanks oilman. Prior to your picking up your message I closed off what I thought to be the faulty automatic bleeds, bled the last remnants of air from the system via the radiator/pump & turned down the pump speed one notch. Hey presto - air no longer entering the system !

So it's two new automatic bleed valves & a few litres of MB1 - not wholesale repiping & a new boiler !

Now if you've any recommendations as to how best to get a 17st bloke into the small gap in the loft conversion where the expansion tank sits I'll be eternally grateful.....

BTR

 

[masona]

Now if you've any recommendations as to how best to get a 17st bloke into the small gap in the loft conversion where the expansion tank sits I'll be eternally grateful.....

www.weightwatchers.co.uk or hammer & saw