Lagging an immersion tank.

SuziQ

I was wondering if any one could advise me on this: I have quite an old fashioned central heating system. I looked into having it all updated last year, but my ex ( a heating engineer) said that in his opinion, what I have is better than all the modern stuff available. He cleaned and maintained the system, the only problem being that he had to remove all the fibrous insulation material from the sides and front of the immersion tank (it's a funny thing-heats the radiators and hot water on gas, or gas can be turned off and you can just use electric in the summer or for quickish hot water eg in the summer.) Obviously I want to replace insulation somehow, but I can't get into it to place an actual jacket around it, as it is in the top of the airing cupboard so I can only sort of slide stuff upwards to insulate it (the fibrous stuff had somehow got into the pipes and was stopping the water from flowing into the bath, hence he removed all the stuff from where he could get to.) The back is still covered in the fibrous stuff but the sides and front are pretty much open and leaking heat-so badly that I can dry clothes in the cupboard with the louvre door closed in a matter of a few hours.Heaven knows how much this is costing me!

The tank does get too hot to touch, so I am bemused by what I can put up around it to stop heat escaping. Does anyone have any ideas what I could use? My ex just shrugged his shoulders and said he hadn't got a clue when I asked him!

keystone

Part of the reasoning for having the HW storage in the airing cupbard is precisely that - to dry and air clothes. Once the tank is up to temp anyway the system should be shut down by the tank thermostat. I doubt its costing you a vast amount of money. I also doubt that it heats the rads as well. What you describe seems to be a bog standard installation with the cylinder on the primary circuit and where, when the CH calls for heat, a valve operates and allows hot water from the boiler to be diverted to the CH pipework. It is likely that such a valve is located close to the cylinder anyway so that pipes around the cylinder will get hot. Of course I could be wrong.

The best you can do is to wrap the jacket around it - get someone to help you. You'll almost certainly not be able to do it on your own.

Are you sure that the fibrous "stuff" in the pipework wasn't actually loose fill roof insulation that had got in via the tanks in the roofspace?

HTH

Cheers

SuziQ

Thanks Keystone-I am only going by what my ex told me-he is a very experienced heating engineer, been doing it over 30 years. Of course-I may have totally misunderstood what he told me lol! The fibrous stuff is what HE put around the tank twenty odd years ago, as he couldn't get a jacket around it after he built the airing cupboard. The system is really old- we bought the house in 1987, and the system looked old then. Every time he thought about upgrading, he looked at what was available and decided what we had was more efficient-it certainly heats this 4 bed house very well when it's running. I asked him again about changing the system last year, as I was considering a combi-boiler, but he advised me against it.He told me to re-insulate the tank when he removed the stuff, when maintaining the system and sorting out the slow running bath tap, which turned out to be full of this brownish fibre. I don't think there is any chance whatsoever of getting a jacket around it as the fit is just too tight in there, and I only have about 10 ins of access at the bottom of the tank. But thanks for you advice!

brig001

keystone wrote: »

I also doubt that it heats the rads as well.

Unless it's a thermal store like this: http://www.simplifydiy.com/plumbing-and-heating/hot-water-storage/thermal-store (I know, unusual, but not impossible - our entire estate has them)
See if the pipe layout looks similar on yours. Is there any way of getting old blankets, coats, sweaters etc. round it? Every little bit will help. You could also check that the pipes are lagged too.

HTH, Brian.

penrhyn

The jckets you can buy come in 4 pieces to fit around the tank, could you squeeze one round yours, other wies maybe a roll of loft insulation, the type thats encapsulated in plastic could be used.

SuziQ

Unless it's a thermal store like this: http://www.simplifydiy.com/plumbing-.../thermal-store (I know, unusual, but not impossible - our entire estate has them)
See if the pipe layout looks similar on yours. Is there any way of getting old blankets, coats, sweaters etc. round it? Every little bit will help. You could also check that the pipes are lagged too.

Not sure, Brigg-our taps do have water straight from the mains, but we have little power to operate a shower, unlike the system you describe.

Penryhn-that looks a possibility! Will look out for something like that.
ETA- Just found these at B&Q -£5.95, not bad at all so will be picking one up shortly, thank you!

27col

I will have to take issue with you keystone. If the insulation on the tank is missing then the tank will rapidly lose heat and this will have to be replaced when the stat calls for heat. If the timer is off then the heat lost will be made up at that point. If the timer is on then the losses from the tank will be made up continuously all the time there is heat going into the cylinder. There are quite obviously severe heat losses because the OP has said that the cupboard is extremely hot. This is only because of excessive losses from the area of damaged insulation. If you compare a cylinder with rigid sprayed on insulation the outside of the insulation is very cool. If you feel the outside of a cylinder with a loose insulation jacket, it is immediately obvious that the losses from the loose jacket are much higher. The OP should make every effort to reduce the losses from the cylinder by whatever means can be found and in spite of the limited space.

erdd2

In the good old days we "lagged" these tanks with old blankets and sheets.....but I am going back a bit

Canucklehead

OP: post a photo to aid ID.

Canucklehead

keystone

brig001 wrote: »

Unless it's a thermal store like this: http://www.simplifydiy.com/plumbing-and-heating/hot-water-storage/thermal-store (I know, unusual, but not impossible - our entire estate has them)

Not all heatbanks are designed to do the CH as well. Those of the tank-in-tank variety do like the one you linked to.

CH is right. OP needs to post a pic.

Cheers

keystone

27col wrote: »

I will have to take issue with you keystone. ...................... snip snip........The OP should make every effort to reduce the losses from the cylinder by whatever means can be found and in spite of the limited space.

Not sure why you are taking issue with me. OP suggested they are wasting vast amounts of energy. It was the implied size of the loss that I doubted but it was only a doubt rather than a definitive statement that she wouldn't be losing anything. Neither do I recollect suggesting that it was a good idea not to lag it. If you re-read the end of my post I did say that it was the best bet.

Cheers