Economy 7 water heater problems, help please!

rosamy52

Hi all,

I've posted a couple of times about my economy 7 hot water heater. For over a month now it's been having problems. It's a 120 litre tank. I'm getting barely any hot water, it's running cold two minutes into a shower and leaving nothing for washing up and nothing for the rest of the day.

It's a rented property and the handyman and two electricians have been out a combined total of seven times now with the landlord coming along on the last visit yesterday as the electrician had told him everything was fine but it clearly wasn't as it still isn't working. The electrician says it's all in working order and three visits ago said "it's working and you'll have hot water in the morning, if I was a betting man I'd put money on it." Well I should have taken him up on that bet because I would have won.

His colleague changed one of the thermostats on the first electrician's visit, before that the handyman changed the little tank/pressure vessel thing. It's made no difference. Second electrician, same company, hasn't done anything particular to it except check the wiring and replaced the switch plate on the wall on Monday even though he said that wasn't the problem. He doesn't seem to know what the problem is though. 🙄 The handyman came on Tuesday afternoon and confirmed there was no hot water from any of the three taps in the flat. Of course when the landlord and electrician came yesterday morning there was hot water because I hadn't used any. They ran the taps and all the electrician could suggest was to run the tap more slowly. I explained that I had done that but it just made the hot water run for ever so slightly longer. And I said there may be hot water now for a couple of minutes but there won't be for any longer. Of course as there wasn't any hot water as soon as they left when I tried to do the washing up.

If you've got this far and can suggest anything helpful for me to ask the landlord to do and how to tackle this I'd be very grateful please. The electrician seems a bit useless frankly and says there are no problems when clearly there are. I've had decent baths from this system before so I know it's possible.

Thanks 🙂

Cardew

Many hot water tanks have two immersion heaters. The top one is to top up a few litres when hot water has run out. The lower heater is connected to the E7 supply.



Are you sure there isn't a problem with the E7 wiring/timer?

EachPenny

rosamy52 wrote: »

If you've got this far and can suggest anything helpful for me to ask the landlord to do and how to tackle this I'd be very grateful please. The electrician seems a bit useless frankly and says there are no problems when clearly there are. I've had decent baths from this system before so I know it's possible.

If faulty or incorrectly set thermostats have been ruled out then the next thing I'd look at would be whether the timer (I assume you have one) is correctly set to run the heater for long enough to get the whole tank up to the right temperature.

If the heater only runs for a very short time then you might get a small amount of hot water in the top of the tank (which is drawn off first) with the rest being luke-warm or cold.

Incorrectly set timings would result in everything "working fine" when tested, but not producing the result you are looking for.

The method of checking whether it is set for the right amount of time will depend whether you have a digital or a mechanical timer... the first job is to find your timer.

Robin9

Are there one or two switches for your immersion (or even 3)?

There may be a master in the kitchen - this should be OFF and controls the Boost (ie the top part of the tank) and you switch this on when a Boost is needed; there may be two by the tank itself - both should be ON.

It sounds like the main part of the tank is not being heated.

rosamy52

The electrician says not, says everything is working and won't seem to acknowledge there's a problem. His colleague replaced one of the thermostats though he told the landlord both of them have been replaced yesterday which I don't think is true as I only remember one being replaced, I could be wrong but I'm pretty sure it was just one as his colleague used my laptop to look up the part, his phone wasn't working so I offered the laptop.
Even if it was there's still a problem I just don't know what it is.

Thanks for replying and any further ideas welcome!

EachPenny

Cardew wrote: »

Many hot water tanks have two immersion heaters. The top one is to top up a few litres when hot water has run out. The lower heater is connected to the E7 supply.

If it were just a case of only the boost element working then I'd expect the OP to get a lot more hot water than that... they appear to only have enough for a two-minute shower.

The last time my main (dual-element) heater failed I temporarily rewired to make the boost element the one coming on overnight. That was giving me more than enough hot water for a couple of showers and through the day hand washing. In fact I only changed the element (after a couple of weeks) because I was concerned about the legionella risk from a half-heated tank. The volume of hot water was more than sufficient for daily needs.

Hence my suspicion about the timings... or else it is a more complex combination of issues which the OP's landlord and electrician have missed.

molerat

Can you post a picture of your consumer unit / fuse box and your meters.

Cornucopia

EachPenny wrote: »

The last time my main (dual-element) heater failed I temporarily rewired to make the boost element the one coming on overnight...

I agree - swapping the wiring between the two elements (if there are two) is well worth doing. Not only should it produce an immediate improvement, but if there is a manual switch for the current top element, then that can be used to test the bottom element and its thermostat during the day when its convenient to do so.

rosamy52

There's no seperate timer unit or switch, only what's on the face of the thermostat I think. The meters are downstairs, it's a block of flats.

Here are a series of photos of the thermostats, the first one shown is the lower one, and the tanks and the meter and meter cupboard.

EachPenny

rosamy52 wrote: »

The electrician says not, says everything is working and won't seem to acknowledge there's a problem....

That's the point I was making. Everything can be working, but not working for long enough.

If the electrician is only checking to make sure the electricals are sound then they might be missing a problem with the timer(s).

E.g. Everything is working when he overrides the timer to test the system, but doesn't work under normal conditions. In my experience that is a classic error when fault-finding timed circuits. Been there, done that.

rosamy52

Ah yes I see what you mean, sorry not having the cleverest morning or day even.