Advice? -Ferroli 701 heating turning off/on?

[bilabonic]

My existing ones read as above.
Around 0.8-1k.
It will fire up on both the old ones when swapped but with the same problem on CH.

The two brand new ones I have off eBay read 11k!! I had 2 as I stated the first o excess faulty.

If you look above you will see I did a resistance test/temp.

It’s not tripping on overheat of the heat exchanger. Or the other over temp.
Both contacts’s are N/C and stating that way.
The frost staying N/O. So that a fine as well.

I can only suspect the. Pump now but how is it tripping out?

How does the is detect flow on the CH?
Both rheostats are fine (yet replacements are not?).

Thanks for replying.

 

[Gasguru]

No rheostats on this boiler, post a link to ebay the thermistors.
On this model there are 2 heating overheat thermostats set at different trip temperatures.

 

[bilabonic]

Correct.
I have replaced both/swapped them. Etc

The only thing is the punp.
It gets red hot after continuing firing