Oven not heating - struggling to find faulty part(s)

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TonyWig

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Hi all. Have trawled the many threads with similar titles without success. Hoping someone can point me in the right direction.

Have a "Harrow HFM55B/2" oven that has stopped heating without warning.
Symptoms are ...
No power light.
No thermostat light.
No internal light.
Clock working.
Fan working (when multi switch is moved to an "on" position)

I have resistance checked the thermal switch, the thermostat switch and the main (bottom) element - all seem OK (though I am no expert with a multi meter).
Putting boiling water in the closed oven, the thermostat "clicks" after a minute or two to indicate it is detecting temperature increase.

I do want to repair this rather than fall back on throwing away a three year old oven both for cost and "environmental" reasons but also do not want to spend hundreds on parts that do not fix it and THEN throw it away.

Any ideas?
Thanks in advance.
 
You need to get it out (assuming it is built in) and get the covers off (disconnect from supply first, obviously!). It is possible that one of the phase links has come loose (loads of ovens have options for running on multiphase supplies in different countries, domestic ovens in the UK would all have these linked across). Or there may be a thermal fuse on the supply to elements (resettable if you're lucky). No way of telling without getting your hands dirty
 
Thanks. Unit is out of housing and back & top are off (so I could test thermal switch etc). I'll have a look to see if I can see anything along the lines you suggest.
Any advice on how I might detect any of the problems you have mentioned?
 
Make sure the unit is disconnected from the mains before you start prodding it with a meter (or your fingers). Disconnected preferably meaning airgapped or both poles isolated and such isolation tested with a known good tester.

The phase links are just that- solid bits of metal screwed into terminals, usually near where the supply cable enters the casing. Visual inspection and check the screws are tight.

Thermal fuse- if there is one it (or they) should be somewhere in the circuit between supply live and the element.
They're usually at the top of the oven (heat rises) and might be hidden by any insulation that is installed. Ways to check- meter set to Ohms (resistance), one meter probe on the supply live line, the other probe onto the element supply cable, mess about with controls until you get a non-infinity reading. Similarly test the circuit from incoming live to the terminals of the on/off switch.

You MAY find there is some control circuitry in the thing that confuses the readings (if switching of the elements is on a triac, for instance- not common but not unheard of.).

Photos of the cabling won't hurt and might make remote diagnosis a bit easier. Manuals appear to be available online but I'm not paying 10 euros for one- you might want to.
 
Have a close look at the contacts and for melted plastic on the multi selector switch.
 
Many thanks for all your help. Unfortunately (for my wallet) the need for hot food won out and we had to buy a new one. Will keep the old one though and keep trying to resolve the problem in my spare time. Again my thanks.
 
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