vaillant turbomax 837 e

[JG123]

hello, i had a phone call this evening regarding this boiler, the customer says when she's running the hot water it goes cold then hot, might stay hot for a little while then goes cold.

any ideas? as i do mostly installs 90% of the time. but would like to get into breakdowns e.t.c any one recommend a course for this?

Thanks in advance

 

[SimonJohns]

thermister or ot stat or plate blocked

 

[JG123]

Ok cheers, do you recommend any courses for this field? also what are the required tools?
Thanks for your help.

 

[SimonJohns]

Don't know tools.

Download mi's. It usually has a step by step guide

No real courses. Just life. Post on here and read lots of manuals

 

[JG123]

Ok, i meant the tools required for fault finding, not to do the job! Am going to pass this on anyway as this is not my field and don't want to play about with it.
Regards

 

[SimonJohns]

Multimeter
Spanners
Screwdrivers
Allan keys
Ldf
Silicone grease

 

[JG123]

ok basic things then which i have. I will get a multimeter, just got the fault finding book from corgi so will get reading and maybe some practice on old boilers we take out!
Thanks for your help anyway.

 

[SimonJohns]

To test thermisters you will need to do a resistance test

If you look in the manual it will usually have resistance values for the temp of the water

But to be perfectly honest. A thermister fault is temp fluctuations. And cannot always be diagnosed with a resistance check