Immersion heater doesn't seem to heat with timer

[DHC6310]

Hi,

I've searched through some previous posts to see if I could find similar scenarios to mine, found a few with very similar set ups but can't find an exact match, sorry if it is there somewhere.

Basically I've moved into a rented property, built 2014, water is heated electrically with a immersion heater (I am not on economy 7). It only seems to heat water when a switch labelled 'hot water boost' is switched on and setting the timer or havin it 'on' on the timer has no effect to the heating of the water and I feel I am wasting a lot of money leaving the 'hot water boost' switch on 24/7 and so want to get to the bottom of why my timer isn't working.

There is an 180 litre Gledhill direct unvented immersion heater in the roof. It has two 3kW electric elements, one towards the bottom of the cylinder and one half way up.
The element half way up is connected to a fused spur switch located just down from the cylinder on the loft floor space.
The bottom element cable runs across the floor space and down into the spare bedroom storage cupboard where the 'hot water boost' switch and Timeguard timer is located.

I'm really not sure what exactly is happening or what should be happening, the timer seems to do nothing when I have the 'hot water boost' switch on or off.
Should I have the fused spur switch in the roof on 24/7 or should I just have the 'hot water boost' switch on 24/7?

I have uploaded some pictures to help show the set up.

Thanks for your help and sorry for my little understanding as this is the first place I've moved into and only just learning about immersion systems.

 

[JohnD]

If indeed you do not have a gas boiler, and the hw is heated electrically, and you do not have an economy-7 type tariff, then you may as well leave the lower immersion heater turned on all the time.

With no cheap-rate tariff, there is no point turning it on and off night and day. It is well-insulated against heat loss.

It is unusual for a house with no boiler, where heating and hw are electric, not to have economy 7 or similar tariff.

However, if your hot-water cylinder was to be heated by a gas boiler, you should let the boiler heat it (gas is much cheaper than electricity) and leave both your immersion heaters turned off, except when the boiler breaks down.

 

[DHC6310]

Thanks for the reply. I don't have a boiler, no gas at all, just electrically heated with radiators and the electric elements to heat the immersion.

Having the 'hot water boost' switch on, which I assume is the bottom element keeps the water hot 24/7.

 

[copea]

However it looks to me as if your hot-water cylinder is supposed to be heated by a gas boiler.

But there's no coil?...
It's a direct cylinder.

The 'HW boost' switch should be connected to the upper immersion and the timer output connected to the lower immersion.
All of it should be controllable from within the main house (i.e. not in the loft).

I'd imagine the fused spur on the floor is a secondary switch.

 

[Newboy]

You have an unvented immersion heated cylinder.

The time switch controls the lower element, the fused spur in the loft should be left switched on, there appears to be a dual tariff meter next to the timer and boost switch - may be providing off-peak electricity at a lower tariff. The time switch needs to be programmed to operate the lower element during off-peak hours.

The 'HW Boost' operates the upper immersion element and provides around half a tank off hot water in the vent that you have used the full tank.

You need to check if the timer is set & fuses to both upper and lower elements are itact

 

[JohnD]

But there's no coil?...
It's a direct cylinder.

yes, I see that now and edited my earlier post.

p.s.
I wonder if that electricity meter is for solar panels? The under-carrier is typical. In which case it would be cheaper to set the timer for, say, 10:00 to 16:00 (if they face south) and heat the water free on sunny days. An Immersun would do it automatically.

 

[DHC6310]

You have an unvented immersion heated cylinder.

The time switch controls the lower element, the fused spur in the loft should be left switched on, there appears to be a dual tariff meter next to the timer and boost switch - may be providing off-peak electricity at a lower tariff. The time switch needs to be programmed to operate the lower element during off-peak hours.

The 'HW Boost' operates the upper immersion element and provides around half a tank off hot water in the vent that you have used the full tank.

You need to check if the timer is set & fuses to both upper and lower elements are itact

Sorry forgot to mention the electric meter next to the HW switch, that is the meter for the solar panels on the roof, just shows how much the system has generated, not linked at all to the immersion (it isn't a solar immersion).

I will try and test leaving the spur switch in the loft on and the HW switch off and set the timer to on just to make sure it's heating with the HW switch off.

I will also check to see if the fuses are intact in the morning.

 

[DaveHerns]

Can't the landlord explain how it works?

 

[stem]

Has the time-guard actually had any on / off settings entered into it, so that it is actually programmed to switch the immersion on and off? It may not have been if there is no economy 7 for it to take advantage of. The red 'on' light will be illuminated when it is set to be on. Does it come on?

However, If your solar electricity agreement is that you are given a set 'feed in' payment for the electricity that your photovoltaic cells generate and which ignores what you actually use, there will be a benefit in having it set to be set to be on when the cells are operating at at their peak output.

There is normally a local service isolator for immersion heaters, I can see one in the cable supplying the boost (top) immersion, so I would expect there to be on for the bottom one too. It's not hidden out of view somewhere is it? In normal use the local isolators would be left permanently on and are used to isolate the immersions during maintenance.

 

[DHC6310]

Can't the landlord explain how it works?

Have asked but just told the timer should heat the water when set. When needed, the hot water boost switch can be used. I will try asking again for a more in depth explanation of they've got one.

Has the time-guard actually had any on / off settings entered into it, so that it is actually programmed to switch the immersion on and off? It may not have been if there is no economy 7 for it to take advantage of. The red 'on' light will be illuminated when it is set to be on. Does it come on?

However, If your solar electricity agreement is that you are given a set 'feed in' payment for the electricity that your photovoltaic cells generate and which ignores what you actually use, there will be a benefit in having it set to be set to be on when the cells are operating at at their peak output.

There is normally a local service isolator for immersion heaters, I can see one in the cable supplying the boost (top) immersion, so I would expect there to be on for the bottom one too. It's not hidden out of view somewhere is it? In normal use the local isolators would be left permanently on and are used to isolate the immersions during maintenance.

Yes I have set the timer to come on at certain times and watched it turn on for the set times, a green light on the top right of the timer next to the red illuminates when on. I've even manually put it in "Overide On" and left it for a few hours and no hot water whatsoever.

You are correct about the solar cells, whatever is generated we can utilise and anything we don't use is sent to the grid and the landlord gets payed for that so it would be best to utilise as much of the solar electricity generated as possible by trying to set the immersion to be heated during daylight hours.

Edit: Also, mentioning the isolator, I've had the isolator for the top element that you can see in the off position and the hot water boost switch downstairs on and the water has heated up. When the hot water boost is off the water eventually goes cold. Did that to test what happens when that spur switch in the loft going to the top element is off.
From what I understand the top element should be the hot water boost but why is it then still heating up with the isolator off in the loft and the hot water boost switch on downstairs?

 

[andytw]

Sounds like the heating element that the timer is connected to is faulty or its trip has popped out. If you were my tenant I would expect you to call me.

 

[stem]

I think you will need to have someone physically check the wiring to see what is connected to where. Otherwise we are all guessing.

 

[DHC6310]

I think you will need to have someone physically check the wiring to see what is connected to where. Otherwise we are all guessing.

Had someone round today to check the wiring.
Basically it's been wired the wrong way round.
The Hot water boost button is turning on and heating the bottom element while the timer is wired to the top element and is wired the wrong way round again so basically, when the timer is "OFF" it is actually turning the element on and heating water while when the timer is set to "ON" the element is off.
So re-wiring is needed.
Thanks for all your help guys!