Potty Netaheat, testing stats?

Went to a job today to fix a problem with the temp of someones DHW. The DHW was supplied by a thermal store ('Boiler Mate') and basically the flow to the cylinder vwas only 60 degrees and isolated the prob back to the Potterton 'Netaheat Profile 50'. The boiler was cutting out at 60 degrees, phoned potty tech help and they said 'boiler' thermostat.

The question is as this boiler has three stats - hi-limit (wasnt this as the reset button remained loose), boiler stat and hot water stat (thats what it was called on the wiring schematics) How do you isolate the problem to a specific stat. Are there basic test that can be carried out to test that a boiler stat is operating correctly?

Why dont you do what they say.

The boiler only has one stat that actually controls the temperature of the water during operation.

The overheat reset will trip at 105 so not that and the pump overrun stat will make the pump run on after the timer has been switched off, well on a fully pumped system anyway.

If you are really bothered get a bowl of water at 60 deg and then put the boiler stat probe in it and see what temperature it clicks off at.

If its any good it should get to about 80 deg at maximum.

Stan

I'm the 'lacky', so i dont really care about which stat has to be ordered etc, just wondering if there were any basic tests that would have ID'd the stat responsible befor calling 'tech help'.

or does everyone just phone tech help and really on their advice? (some of them apparently talk shyte )