dimplex storage heater with low heat output

[Jonboy73]

I've looked at a Dimplex XT24 (4 element) storage heater.  It is warming up but not putting nearly enough heat out.  That led me to think 1 or more of the heater elements had gone....which also stacked up with the tenants view that the ends of the heater were cooler / hotter in the middle.

(With all power off) I tested the resistance across each of the heater elements contacts (all 4 of them get 20 ohms) and I get 58 ohms across the L&N terminals.  With 20 ohms at each element, I'm guessing that these are all OK?  What else can be replaced on these heaters.......is there more than 1 thermostat?  What result should I get if I test resistance across a good stat (or conversely, what would I get if the stat was faulty).

Any help appreciated, thanks. Jonboy

 

[ProDave]

If each heating element is about 20 ohms each , then all 4 in parallel should be about 5 ohms NOT 58.

The charge thermostat could be at fault, switching off at too low a temperature.

There are usually 2 themostats, the normal charge thermostat, and a safety cut out to stop it overheating if the charge thermostat fails. If that has gone, it will not heat up at all. Some safety thermostats can be reset, occasionally you will find a thermal fuse instead.

P.S Who has their storage heaters on at this time of year?

 

[Jonboy73]

Thanks for prompt reply ProDave.  You're right, who has heat on now!  Actually, this was reported to me some time ago, and trying to get it sorted in good time for when weather changes.

So, to prove main stat is good, a continuity test across it should.....read near zero ohms (just a small fraction of an ohm).  I'll try that and see what happens.  Thanks

 

[Murdoch]

Most modern storage heaters won’t heat up fully when it’s warm , let alone the heat we are having now ...........

 

[Jonboy73]

Same Dimplex storage heater.  Where before I could get readings at the heater element terminals, and across the L & N.   Now the results on metre are as follows....

Across brown & blue…..1

Across heater elements (all 4 of them)

-  At 20 on metre……0.01 or 0.02

-  At 200 on metre…0.00

I'm thinking all 4 heating elements must be gone.  Any thoughts?

Thanks,

 

[Ardet R]

The results would depend on units of the scale of the meter.

The 1 indicates there is no continuous path line to Neutral, likely causes being the thermostat has reached its set point (not likely in this case) or the overheat has cut out.

If this is 20kΩ / 200kΩ range then the other readings may be correct.

Each element should read about 85Ω and line to neutral should read about 21Ω.

All four elements failing at the same time is unlikely.

 

[Jonboy73]

Sorry Ardet R, just noticed your reply.  The heater trip had cut out, so that had likely affected readings.  With it reset, it only stayed operational for a week, then stone-cold again.  I think the issue must be a faulty thermostat.  How would I identify if the thermostat was faulty?  Thanks