No HW, problem solved but now won't stop!

[finchy01]

Morning chaps. I had a call with boiler not working from a customer.

2 CH zone valves and 1 HW. All drayton.

Honeywell single channel for hw and 2 danfos tp5 programmer stats for heating. Greenstar 40cdi boiler.

I found one of the heating heads had come off the body, when I reattached it everything fired. No hot wster still as I then found thermal cut out had popped, reset that then it started doing hw too. The boiler then stayed fired constantly when hw on timed (even when advanced so it shouldn't be on) room stats were down at this point so it shouldn't have been heating. The only way I could get boiler to stop was to switch hw pro to off. Even with this though the boiler was cycling on/off constantly.

I was thinking sticky valve but it seems to move on and off with the programmer. Then PCB for Boiler but can't see how a heating valve head being loose would stop the boiler firing.

Am I missing something obvious?

TIA

 

[Darren Jackson]

Pre-heat function? or frost stat faulty maybe?

 

[Gas74]

Sticking end switch?? Check at wiring centre

 

[mfgs]

Time to get the multimeter out and test for voltage to see and what is powering up the boiler.

 

[finchy01]

Time to get the multimeter out and test for voltage to see and what is powering up the boiler.

To be honest my fault finding is my least strong point. Something I have been meaning to address for a while. I'm booking onto the Baxi and Honeywell courses over the quieter summer months. Any other courses anyone would recommend? Sorry to go off topic. Thanks for your answers. I was hoping I was missing something simple

 

[mfgs]

The Honeywell course is good. Fault finding on controls is easy. It's just a series of switches allowing power to the next stage. If you understand the sequence then you are half way there.

 

[Gary80gas]

Its difficult to recommend training courses, you always pick a few things you didn't know and you get a degree of familiarity with the boiler, but generally they are a real let down. They could teach you so much more, they really could, but spend half the day in a sales pitch and then they think there your mate doing you a favour sending you home at 3.30pm. Baxi was the only one I was impressed with. Enough grumbling.

 

[sammathias]

vaillant courses have been by far the best!! all the time in the world for questions etc and the blokes are in no rush at all to get home. Yes they big up their products but atleast they show you in depth how to fix them.

oh and the lunch and coffee machine is spot on.