Isar constantly switching to test mode !

[TIESTO.]

Like the heading says when ever the boiler decides it goes into test mode sometimes forgetting to end the T mode by itself.
Its an isar He35 that otherwise runs Ok except when in Dhw mode the rads heat up is this normal for this boiler or is the motorised valve playing up

 

[corgiman]

have you got a dripping tap?

and the diverter valves knackerd

 

[TIESTO.]

Thanks for replying.
No dripping tap but the valve problem is it an expensive one.?
I was hoping the rads warming up was the boiler dissapating the heat build up.

 

[corgiman]

usually the T is indicating the boiler heating up the plated heat exchanger, I cannot see the div valve doing this.

Mebbe the others have a clue?

 

[gas4you]

Try turning off the cold inlet under the boiler and see if it still keeps pre-heating.

If it stops it proves you have a leak or drip somewhere.

 

[gas_man_gaz]

id say ya diverter is passing and the boiler is warming up all the rads on pre-heat instead of just the primary circuit. jus remove the motorised head and check the valve isn't stuck