Telford tempest water heater

[bullethead123]

Hi all,
I'm considering buying a flat which has a Telford Tempest hot water cylinder. There is what seems to be an expansion vessel sitting above it and an immersion heater below. I've not seen one of these before, can someone explain how it works?
Thanks, Chris.

 

[bullethead123]

Some pics

 

[Rodders53]

Looks to be an indirect unvented cylinder being used in electric direct mode.

Tempest Stainless

www.telford-group.com

Mains pressure CW in --- HW electrically heated out from top. Expansion vessel has air in and flexible bladder to absorb the water expansion.

Unvented HW cylinders need regular maintenance of EV pressure etc.,. Google/Bing will explain more fully how they work if needed.

 

[bullethead123]

Mmm, Thanks for your response Rodders. So the system is designed to pump water heated in a boiler through a coil to heat the water in the tank? Thing is, there is no boiler in the flat so it must be using the electric element only to heat the water no?
Is this efficient?
Would I be better off removing it and replacing with an insulated standard electric element type immersion tank?
If so what's parts and fitting likely to cost?
Cheers

 

[Adam_151]

Would I be better off removing it and replacing with an insulated standard electric element type immersion tank?

That would just be the unvented version of the same (cyclinder with the coil blanked off and using electric elements for heat). You would loose the pressure advantages of the unvented set up and also have to find somewhere for a header tank (unless you went for a fortic type cylinder)

I'm not sure what you hope to acheive, but the only thing which would be a worthwhile change is a move away from electric restive heating to heat the water and to do it with natural gas or, heat most of the way by heat pump and top off with restive heat, alas I fear neither would be posisble, if gas was an option it would likely already be in use, and heat pumps arn't really possible in flats unless designed in from the start (and drilling for ground source *really* ****ess off your downstairs neighbours....)

 

[flameport]

Is this efficient?

It's as good as you can get for electric only. Hopefully it also supplies a shower as well as the taps.
If there is an electric effort installed, it can be thrown out and replaced with a thermostatic mixer instead.

removing it and replacing with an insulated standard electric element type immersion tank?
If so what's parts and fitting likely to cost?

Well into 4 figures, to achieve the substantial downgrade of extremely low pressure, low flow, and exactly the same operating costs as before.

 

[winston1]

Is this efficient?

Yes. Electrical heating is 100% efficient. But it is not cheap as electricity 3 1/2 times the cost of gas.

 

[bullethead123]

Thanks Adam. I was showing my ignorance there. I noticed there was no header tank but did not put 2 + 2 together. of course, the water pressure has to come from somewhere. I didn't run any taps either. I just assumed the pressure would be weak. Another viewing needed I think.
I think the cylinder was put in in 2017 (at least that's the date written on the cylinder itself) so I guess it will be relatively well insulated. Can someone confirm this please?
Seems like the cylinder is a plus point.
There is gas to the flat but it has been capped off.
The flat is heated by electric radiators and it has an EPC score of D (63). If I were to install HHR storage heaters, would that bring it up to a C?
I guess I'd need 4 or 5. Two in the lounge, one each in the bedroom, hall and perhaps the kitchen. I'd need an economy seven supply, a consumer unit and suitable wiring installed (have I left anything out?) Can anyone advise on what the likely cost of all that would be?

 

[bullethead123]

The flat is in Sutton, South London.

 

[winston1]

As gas is available the best upgrade will be gas central heating. You could still keep the cylinder.

 

[oldbutnotdead]

As @winston1 your most cost-effective upgrade will be get gas reconnected, get gas boiler installed to heat that tank and to heat the rooms (radiators or warm air).
If the flat is in a tower block make sure there is still a gas supply into the building (was it Ronan Point that caused gas to be banned in some types of high-rise? Do check it out).

 

[Rodders53]

Insulation:
Read the Tribune link... it specifies the heat lost per 24 hours for all sizes...
But those style are about as good as you get.
Never any harm in adding extra lagging and on the HW pipes exiting especially as they'll be additional loss sources.

It was either cheaper to buy an indirect rather than a direct tank for some reason; or a lack of direct cylinder stocks when installed.

Leccy to immersion heater is 100% efficient conversion process, but leccy is more expensive than most fossil fuels.

I'd run a mile from any single-rate all electric flat. Heating will be a big expense.
E7 type tariff and modernish storage heaters / water heating off peak might not be so bad...

 

[Harry Bloomfield]

The flat is heated by electric radiators and it has an EPC score of D (63). If I were to install HHR storage heaters, would that bring it up to a C?

None storage electric heaters are usually installed by landlords, for the landlords benefit, convenience and to save them outlay. The tenant or purchaser pays for that saving in paying much more for their energy bills. If only electric is available, it would need storage and an off-peak tariff to make it more economically sensible.

 

[Agile]

This would have been better on the plumbing forum.

However it looks as if this cylinder already has a secondary heating coil and so could be heated by a gas boiler if you had one installed.

Heating the flat by gas will be about a THIRD of the cost of electricity!

That can justify a significant expense to fit a boiler and some rads.

But do not wait too long as gas boilers will become illegal to fit in a few years. ( I expect there will be a black market in fitting second hand gas boilers for a few years afterwards. )