Ongoing storage heater problems - some help would be much appreciated.

[jedisparks]

Have an on going problem with a storage heater (Dimplex CXL24N). I've been out to look at it 3 times now and the occupier says that it still isn't working properly.

I was originally called out to it because it didn't work. The thermal reset had gone (not uncommon) and the thermostat did not look in good shape, So I ordered a new one and fitted it (2nd visit). During this call I had all the elements out to take a look and test resistance and IR. They all had similar resistance accross the elements.

Then I got called back becasue the heater wasn't getting hot enough and on attending I agreed and would have expected it to be a bit hotter than it was. So I wondered if one of the elements had gone. However on feeling the front of the heater It didn't feel like one area was cooler than the rest. Also, the resistance accross the whole heater was 17.8 ohms which I figure to be about right. 240/17.8 = 13.48Amps, 240 x 13.48 = 3.2KW. So, for a 3.4KW heater that seems about right...??

Anyway had another call today to say that it still isn't right and I don't really know where to go next. I'm doing this for a landlord, in one of his rentals. So far I've attended 3 times and paid for a new stat but can't really charge him if I haven't fixed anything. Here is a list of what I have checked, have I missed anything?:

1) Stat - replaced with a new one
2) thermal cutout - reset
3) Elements - removed, examined for damage, continuity and IR tests satifactory
4) Isolator wall switch - Replaced as I did find a high resistance accross the neutral terminals
5) Checked continuity of supply cables from consumer unit - checked out fine
6) Got rid of all the dust inside the heater
7) Asked if they dry clothes on the heater - Occupier says no, but sometimes puts their socks on the back, not covering the air vent (I'm a bit suspicious of this but it doesn't explain what's going on).
8) Is it the time clock - the clock is inaccessible. However there is another heater in the flat which is working fine.
9) Checked resistance accross the whole heater from the isolator switch (in the off position) got a reading of 17.8 ohms
10) Fuse protecting the circuit checked out fine
11) Continuity from the busbar to the outgoing terminals on the fuse holder tested fine.

Basically, I'm stumped. any ideas?

Thank you.

 

[Octopus]

deleted. reread post!

 

[Hants-Spark]

When you say changed stat, does that include the capilliary?

 

[jedisparks]

hi hants-spark and thanks. No I didn't change the capilliary. Do these go wrong and sometimes cause a problem?

 

[44ALLAN]

When you say changed stat, does that include the capilliary?

capilliary isn't touching one of the bricks or a 'hot spot' ?

 

[Hants-Spark]

Its been a while since I've done any work on storage heaters but yes they can fail and cause the problems you are having, I would replace that and see if it makes a difference. Good luck

A good call from 44ALLAN also.

 

[jedisparks]

Ok thanks, The existing one isn't touching any bricks or hotspots, so replacing that could be the next step.

I did wonder whether it might be worth replacing the accelerator unit too, but not sure if these go wrong either.

I've been fiddling with storage heaters for years and it's usually been thermostat, cut out, elements, isolator siwtch, or fuse. So, this is a new problem for me.

 

[Dcf]

Here is a method that works for me.
Get a length of flex attach it to the removed faceplate
Plug into nearest socket. Get clamp meter and stick on neutral of flex
Operate charge control to see if it's working correctly it will flash if it is
Check load which for a 24 will be between 12 and 14 amp.
This method checks the elements charge control and switch in a five minute operation
Least it's a dimplex unlike the creda I had to fix yesterday gash it was

 

[Hants-Spark]

When you say the accelerator unit, that maybe what I call the charger unit which located at the top by the switches etc. We generally changed that with the capillary as a job lot. Didnt have many problems after that. When ever I carried out repairs with heaters it was very rarely anything else other than the charger/capillary or stat, on occassions resetting the cutout when people drying clothes on them. Hope this helps.

 

[jedisparks]

Thanks Dcf, Yes I will try that. When you say 'flash', I take it you mean a small flash when you turn the stat on, as it contacts?

What do you think about the capilliary thing?

thanks again

 

[Dcf]

Yep the flash when the charge control makes and breaks.
Never really had any problems with capillaries I must say.
I have had faulty charge controls from new though
Just make sure the stat clicks in and out sometimes if they are turned too far down they don't want to come on make sure it clicks on and off.
They are a pain in the arse at times these things

 

[jedisparks]

The accelerator I think is some kind of resistor and sits behind the control knobs usually an inch or two away. Never been quite sure what it does LOL!

 

[monkeyelectric]

I think after 3 visits and all the messing about you just as well replace the whole damn thing!

 

[Guitarist]

I think after 3 visits and all the messing about you just as well replace the whole damn thing!

Probably work out cheaper.

 

[oldtimer]

Well you have done everything by the book and for me 45% is the control stat/high temp module 45% the switch then 10% clothes on the heater

 

[jedisparks]

Might end up doing this. I will price it up for the landlord and let him choose between doing that and more visits from me and more replacement parts.

This job has been bloody annoying to say the least.

 

[BrianDB9]

If thermal cut out had gone to begin with why ? They dont just have to restrict air by drying clothes on the heater , its enough to restrict airflow by putting a clothes airer round the heater.
The most common problem with storage heaters i find is user error.
Make sure they are closing the output at night or it will run out around 4 PM and they'll say it doesnt work, are there signs of condensation in the room - if there are they probably are drying clothes in there regularly.

 

[markythesparky]

Could I offer another test?

Why don't you run a circuit from a 32a overdue rent device in the peak rate board to the off peak board. Take out all circuits on the off peak apart from the one feeding this heater.
Switch the circuit on. Then you can test everything and wait to see how hot it gets.

To be honest when I've dealt with these its more after than not the div tenant not knowing how to use it and not even turning the input heat up.

also another stupid thing they do is leave the output flap up when the the heater is on over night? The heat just goes straight out of it.

Best thing is to ask the tenant to describe to you how exactly they are using it. Don't give them any prompts.

Bet its their fault.

 

[markythesparky]

That should say peak rate and not overdue rent

 

[R G]

There is a capilary stat a the back of the heater near to the cable entry , and its on a slidding plastic flap , this should be lowered usually when the feet are put on the heater, it could be that it has'nt been lowered and is picking up the higher temperature , this stat is to sense room temperature during charging