I need help to detect an AC burned heater element

[Nicmus]

One other approach will be to do a search in this forum for “transformerless” you will find ideas of simple circuits of powering up small loads (a LED part of the optocoupler in your case) .
Use one of the circuits in parallel with your switching device (relay, triac,…etc) and monitor its control signal and the optocoupler output.
If your heater is OK you will have a signal from your optpcoupler when the heater is not energzed. In case the heater is open you get no signal when the controlling device is OFF.

HTH

Nick

[igeorge]

Thank you Nick
I will look on this too. It might be a good solution to get rid of the power components problem
Regards
Ion

[Nicmus]

Using one of the modules, suggested above, parallel with the switching device and one parallel with your load and ORing the outputs of the optocouplers (preferably open collector type) you can have all your parts inside your machine and the only connections to the monitoring device will be two isolated wires that will act as a “switch”. The only time the “switch” shows open will be when your heater is open.

Nick