On Monday, 1 February 2021 at 14:16:00 UTC, Mike Gibbons wrote:
On Monday, 1 February 2021 at 12:18:46 UTC, Nick Odell wrote:
On Mon, 1 Feb 2021 10:41:14 +0000, Clive Arthur
wrote:

On 31/01/2021 21:00, Alan wrote:
On Sun, 31 Jan 2021 12:24:47 -0800, Mike Gibbons wrote:

Hi,

I have a Hotpoint AHP662X built in oven with a fault. If anyone can
help with the diagnosis I'd be very grateful. Here's what happens:

1. Turn on oven - normal fan setting.
2. Oven warms up normally, thermostat clicks and the heating up light
goes off.
3. After a while - 10 to 30 mins - oven goes off entirely. Fan stopped
clock display goes off.
4. A few minutes later the power comes back on.
5. Oven works for a while before repeating the cutting out cycle.


The Overheat thermostat or its fan are a likely cause. Has it got a case
fan, not for cooking, but to keep the electrics cool? This is normally a
100mm or so fan on the back casing.
It is controlled by either a timer pcb, or a stat. If the internal casing
overheats the stat cuts all power.
Also, on some ovens, the overheat stats for the oven also cut all power.
Check the fan first if it has one, then the 2 or 3 stats.

And try running the oven at a lower temperature - say 100'C - and see if
it still cuts out.
Apologies, Clive. I hadn't seen your post when I wrote exactly the
same thing.

Nick
Hi,

This morning's test:

1. Set temp to 60 degrees with a thermometer in the oven
2. Oven warms up until thermometer shows 52 degrees. Thermostat clicks off. Temperature stops climbing
3. Temperature drops to 47 degrees. Thermostat clicks back on.
4. Thermostat continues maintaining the temperature at about 50 degrees. Oven remains on - tested for 40 mins - normally would have cut out by then.


My conclusion: main thermostat is behaving correctly (at least at 60 degrees) .

I think the next step is to take a look to see if there is a case fan.
This afternoon's test:

1. There is a second fan next to a chimney at the top of the oven - everything looks clean and in good condition. It is connected via a temperature sensor in the chimney. I heated up the sensor with my heat gun and after a minute of so the fan turned on - the oven was not switched on.

2. I turned on the oven at low temperature. Used my heat gun to heat the overtemperature thermal cut-out located next to the element. After a minute or so the oven cut out - exactly the same as the fault I have. It came back on a few seconds after I removed the heat gun.

3. My prognosis a) faulty overtemperature cut out operating at the wrong temp b) something else cutting out when things get hot.

4. Proposed course of action: replace the overtemperature cut-out and go round all the connections I can see to make sure they are secure.

How does that sound? Any other ideas?

Thanks again, Mike