Economy 7 Water Tank - tepid water only

[mandylooo]

Hi,

I have problem with my water tank. The system is electric and runs on Economy 7 and is currently only heating water to what I would call a tepid temperature, but it does appear to be heating the water to some degree. We have an immersion heater which we have been using to top up the heat, but this is not ideal. When the 2nd element was fitted we deliberately didn't tinker with the immersion so that we knew the next morning whether the water was warm from residual heat from the immersion.

Since this problem occurred we have tried the following:

1) Replace the thermostat
2)Adjustments to thermostat settings
3)replacement element (the element had been replaced at the beginning of the year anyway)
4)tested the economy 7 by running a storage heater - this worked fine.
5)more adjustments to thermostat settings.

The plumber who replaced the thermostat and element has also taken a look at the electrical connections and believes they are fine, but admits to not being an expert.

I'm at a loss to know what to try next. The tank itself is 4 -5 years old.

Does anyone have any suggestions?

Thanks.

 

[seco services]

take it your talking about the bottom element the night rate one ?

 

[mandylooo]

yes, that's correct. it's the night rate/Economy 7 element which isn't doing its job and this is at the bottom of the tank.

 

[seco services]

can't see why if your economy 7 is giving power 12pm to 6am
the timer is only a means of seperating the immersions for different times.

whats the stat set to ?
they are wired round the right way ? bottom to night rate ,top to boost.

 

[mandylooo]

The stat (thermostat?) has been adjusted through its full range without much affect seen (if any).

The elements are wired correctly - when the immersion is turned on during the day we get hot water.

 

[seco services]

The elements are wired correctly - when the immersion is turned on during the day we get hot water.

what one comes on in the day top, bottom ?
are they wired to a economy 7 timer ? what timer is it ?

an immersion is only like a light bulb its on or off.

 

[mandylooo]

The top one (immersion) comes on during the day.

I don't know what type of timer is used for the night-time (bottom) element. It wires directly into the wall and, as with all the Economy 7 items in the house, appears to be on a separate circuit - there is no apparent timer, but all wire into specific plates for the Economy 7 which only come on at night.

 

[seco services]

i'd be inclined to get the economy 7 checked out as you have had two elements and the latest ones not that old.

 

[mandylooo]

Thanks. I'll try to get that looked at, though the fault must be localised to the hot water as the storage heaters are working.

 

[seco services]

its just how you have changed them and still the same.
and they are not tripping
useally they work unless they are breaking down inside or scaled up.