combi boiler with emmersion heater help please

[happyhero]

Hi I used to be a building services engineer so had training in many fields but not expert in all (had some plumbing training and quite at home with doing my own) but I now work as a fully qualified electrician.

In the house (a friends house) I am working now they have a fairly new Worcestor Bosch wall mounted boiler and while I was working on the electrics I found this supply with a switch that had been taped off. Tracing the cable I found that it fed an emersion heater in the bathroom and obviously they no longer use it if it has been taped off for ages. The supply is messy and I want to remove the cables and burnt out switch but the emersion heater still has plumbing to it. I explained to them how some people keep their emersion heater in case their boiler ever fails but where I am lost is do you do this with combi boilers too, or is it a no no with combi's due to altered plumbing etc?

Also they no longer wants the emersion if it can be removed but what is the situation with the plumbing?

Would the water still be going through the emersion pipework or can they be capped off at every joint back at a suitable point? Basically they would like the cupboard space. When I had my combi fitted ages ago I had all my tanks and emersion removed and it was great as it gave me all this space back.

Any help appreciated.

 

[JohnD]

it is possible, even with a combi, to have it heat a cylinder. This can give fast bath or shower flow.

this is not very common.

it's unusual to have a cylinder remaining if not in use as the plumbers like to tot it.

is the cylinder full, and is it hot?

 

[happyhero]

Hi JohnD

Cheers for the help.

I will have to check for sure but I would say it is not hot because I was working by it for a while and think I would have noticed ie I touched the old element and that was cold. I would say it may have water in it simply because all the pipework is still there but again I will try and check that.

But could it be capped or would I be putting a block on the system by capping off at the heater? would I have to connect the in's to the out's to maintain everything if I tried to remove it?

 

[JohnD]

It is probably unused, but you would have to see if there are any pipes going to it from the boiler for Primary circulation and if they are connected at the boiler end. If not they are probably redundant and you could remove the lot, but it is an ususual condition so I think you will have to puzzle out what has been done by inspection.

You will need to check if the hot taps are all supplied by the combi, and if there is a cold tank in the loft, what is it doing (if anything)

 

[happyhero]

Ok cheers JohnD but why would you ever want tanks in the attic which they do still have if you have a combi, what would they be for?

 

[fumb]

Mostly for the bath

With older or smaller combis flow rates are not good. Often well less than 10 l per min. This means filling a bath takes ages. My friends moved into a place with an old ideal combi (oh woe are they). It takes a good 10 mins to fill the bath, although bath is a GBFO thing!

So you leave the hot water cylinder just to feed the bath. Wire it in a a separate zone on the heating system and bob's your uncle. You have mains pressure everywhere but still have a good bath fill

If you turn on the bath hot water does the combi fire? Sure fire way of telling if it's plumbed up as above unless it's on a very very odd setup

 

[happyhero]

Cheers fumb, I think I will have to go back and check a few things and then maybe come back on here. Thanks for all the help guys