Two Water Tanks in Attic

[budest]

Hey guys,

Need some professional advice here.

Sister moved into a house a few weeks back and I was putting stuff into the attic and noticed two water storage tanks. One large one with a smaller one on the top of it. Looked quite bizarre to me having never seen anything like it before. In my research I have learned that the larger tank is the cold water storage and the smaller one is part of the overflow for a vented heating system - correct so far?

Well the smaller one had quite a bit of steam coming from it which had caused considerable condensation on the felt and rafters so this had been going on for a while. The lid was also left off this tank.

The larger water tank housing cold water also had no lid on it (and still doesn't as I can't find it) which has concerned me given that all the dust and whatnot from the attic is free to settle on it and whilst I appreciate that this isn't for drinking I am still concerned about it being open. There is also some sludge or something at the bottom of it which I am lead to believe is normal. Is this correct?

Sister got a plumber out who didn't get into the attic when he discovered that the boiler stat was set to the highest (fully right as the knob is missing). He said that it needed to be lowered and what was happening was that the system was running too hot and that was causing the steam in the attic.

So can anyone advise me on the following:

1. Should the hot tank be placed directly on top of the cold tank?
2. Having lowered the temp on the boiler the steam is still present in the attic - what else could cause this?
3. Is it acceptable to have no lid on the cold storage tank? If not what are her cheapest options to sort that problem?

Sorry for the long post guys but I am trying to give you as much details as possible. I took two photos when up there but they aren't the clearest given the lighting:

Any help at all guys would be very much appreciated.

 

[Newboy]

What you've described is standard for an open-vented heating system and a low pressure (stored) cold water system.

The steam coming from the expansion (smaller) tank is a sign that the system isn't in good condition - more than likely 'pumping over' which may be due to poor circulation - suggest you get a decent heating engineer to take a good look at the system.

Both tanks need lids on it to prevent all sorts of muck and debris falling into them. Tanks and associated pipework should be lagged to reduce the chance of freezing.

 

[budest]

Thanks for the reply.

Is it OK to have the tanks positioned on top of each other as seen in the picture?

 

[Newboy]

Can't really make anything out from the pictures!

The main factors are: ensuring that the tanks are on a decent flat base, have overflow/warning pipework correctly sized and connected and are fully supported.

 

[nortonj]

The tanks should not be on top of each other like that doesn't look stable at all. Cant see a reason why anyone would do that. Is space an issue?

 

[budest]

The tanks should not be on top of each other like that doesn't look stable at all. Cant see a reason why anyone would do that. Is space an issue?

No there is space there for both of them to be placed side-by-side but the purpose built wooden base they currently sit on would need extended.

What looks to have happened is that whoever fitted the tanks took the lid off the cold water storage tank as it wouldn't support the weight of the heating system overflow tank. Then instead placed two pieces of wood over the cold water tank and put the hot water tank on them. I'm no plumber but it looks like a bathed job imo.

For my OCD to be satisfied I would like to see both side-by-side and a lid placed on the cold water tank and the overflow issue sorted which is causing the steam.

Are there any heating engineers on here from Belfast you are aware of?