Electric water heating

wolfe111

I was wondering if anyone could help me. I’ve currently been living in my 2 bedroom 1 bathroom flat for 2 months and it looks like my immersion heater needs replacing as the fuse keeps blowing whenever I have it on. I can get it repaired but it looks like it will cost £750+ including fitting. I’m curious if anyone has been in a similar situation and has any advice on what to install as I find an immersion heater is costing a lot to run.

I’ve seen domestic hot water heat pumps like the valiant aroStor and Dimplex Edels and was wondering if they were efficient in the uk? Or if an instant electric water heater heats up water hot enough for showers in a single phase metered home? 

Thanks in advance, any suggestions are appreciated. 

Krakkkers

If its the element then you can get a replacement from B&Q or similar for £20 to £30 and fit it yourself.
I did mine and just followed a Youtube video.
I cant think what else it could be.

And i think that would cause the fuse to blow.

TheElectricCow

By "the fuse keeps blowing" do you mean the literal fuse in a fused spur suppling power to the heater is blowing when in use, or that it's tripping the circuit breaker?

Immersion heaters typically don't have many components and the actual elements are relatively inexpensive (and theoretically not too difficult to replace) for a straight swap out I wouldn't have thought it'll cost anywhere near that price unless the tank/pipework/wiring is also in need of replacing. A quick search suggests £100-300 is the sort of price range for this job to be carried out by a professional, although a competent DIYer could likely tackle it without too much trouble for a like-for-like replacement.

Rob5342

It depends how old it is. An element doesn't cost much but it can be difficult or impossible to remove the old element if it's an old cylinder that is scaled up.

Swipe

The OP may also need an immersion heater spanner to get the top off the tank if it hasn't been removed for years. Pretty cheap though on amazon https://www.amazon.co.uk/immersion-heater-spanner/s?k=immersion+heater+spanner

Oh, and make sure they empty the tank first.

Jonboy_1984

There are normally two parts to hot water tank element:

 A thermostat along these lines https://www.toolstation.com/tesla-dual-safety-rod-thermostat/p32682 that is two wires to replace and is no more complicated than changing a plug or light fitting. They can fail open and let lots of electric current through, causing a trip. Note they normally have a little thermal cutout reset button and it may be worth pressing that with a small pointed object to try resetting it first. They normally have a model number on the top so you can buy the correct length. The electric supply must be off before looking at them.

The heating element that looks like this https://www.toolstation.com/tesla-long-life-incoloy-immersion-heater-resettable-thermostat/p65632  (The above thermostat sits inside the middle leg). These can physically corrode away over time . One our old one, in a hard water area, the main element had completely broken off and caused the trip switch to keep tripping as the electric had direct contact with the water.
 As the tank gets older it gets more limescale and they seem to wear out quicker. They can be changed on a DIY basis but do involve basic plumbing and then the same wiring as the thermostat above. As per above I would look at YouTube. 

Where it can go wrong is if the fitting is tight it can crease the hot water tank and cause a leak resulting in a new tank being needed.

wrf12345

On-demand heater may be a better choice or perhaps use one of the tradesmen sites where they bid for the job. Or just don't use hot water...

doodling

Hi,

Swipe said:

The OP may also need an immersion heater spanner to get the top off the tank if it hasn't been removed for years. Pretty cheap though on amazon https://www.amazon.co.uk/immersion-heater-spanner/s?k=immersion+heater+spanner

Oh, and make sure they empty the tank first.

The usual advice is to make sure that the cylinder is drained to below the level of the immersion heater fitting but, within that constraint, to keep it as full as possible.  This helps the cylinder resist creasing or moving around as you battle to loosen the old immersion heater.

If the cylinder is a traditional copper one then it is worth considering its remaining life as, depending on the water, they can corrode or scale up through use (although if it is only used with the immersion heater then most of the scale will be on the element).  If the cylinder is stainless then it should have a much longer life and it should also be a little more mechanically robust so less chance of damage when you remove the heater.

To go back to the OP's question, the heat pump cylinders will take heat from the inside of the flat to heat the water unless they are ducted to outside.  Only the OP knows whether such ducting is physically possible and would be permitted by the lease. Whether this is cheaper than direct electrical heating will depend on how the flat is heated.

If you have a bath then there is no practical alternative to stored hot water (even a gas combi boiler isn't great and those can generally deliver 1.5x to 2x the power of electric instantaneous heating).

If you only have a shower then you could get away with instantaneous heating at point of use.  Personally I find that an electric shower is a tolerable rather than a pleasant experience, especially in winter, but that will depend on your showering preferences.  Note that if you use instantaneous electric heating then it will orly be marginally cheaper than using a cylinder as the only cost difference is the storage losses which should be low with appropriate insulation.  If you are on an economy 7 or similar tariff then using instantaneous heating will.be more expensive unless you use the majority of hot water during times of cheap electricity.