Economy 7 - Hot water not working

Heely

We had no hot water in the morning so we replaced the lower immersion heater with a new one. The old one we removed was burnt by the screw.
However, with the new one the water is still not hot. When I use the booster switch I get hot water but its expensive. Please can anyone help. Thanks

tim_p

Did you replace the thermostat too?  Usually slides into a hole in the middle of the element?

Robin9

Check in your consumer unit - is there a separate Circuit Breaker for the bottom immersion heater.  If it has operated to OFF switch in ON.

Heely

Thanks for replying. The circuit breaker is switched to ON

Heely

@tim_p the element has a built in thermostat (I think). 

Heely

This is our Consumer Unit

Robin9

An obvious question (to me anyway) - the bottom element is switched on isn't it. You do realise you won't get hot water until its heated up overnight.

Heely

Pic of the (old) immersion heater with thermostat. We replaced with a similar one

avoidtheupsidedownbottles

What have you set the thermostat dial to?

tim_p

Heely said:

@tim_p the element has a built in thermostat (I think). 

Maybe worth checking, and check it’s at a sensible setting while you’re at it. Thinking about it, if there wasn’t a stat in there then the thing should come on uncontrolled with the E7 and you’d hear the tank boiling at some point! How does the immersion get wired in? Through an isolator switch? Fused spur? Couple of extra things there to check. 

Heely

Robin9 said:

An obvious question (to me anyway) - the bottom element is switched on isn't it. You do realise you won't get hot water until its heated up overnight.

Yes, the bottom element is switched on. However the Water Heater switch (on the wall)  DOES NOT come on during off peak hours (23.30-6.30hrs).
The light comes on only if I use the booster during the day (see pic)