Vokera Lines 24

[mondo123]

Vokera Linea 24 old!
No DHW it only goes up to about 30deg on the display then flame goes out and repeats when in DHW only mode.

-In ch mode the heating seems to work slightly better but still no DHW
-It had an ignition pcb fitted last time it was serviced
-I have swapped both thermistors which both read 9ohm(dhw) & 10(main)ohm when out of circuit (the dhw therm was covered in limescale build up)

-I also cleaned out and checked the seals and pressure switch parts (the -
circuit was very dirty and seals have seen better days).

-I am thinking of ordering a new seal kit and diaphragm etc + thermistors?
-If this don't work then maybe call the lads out for a pro opinion

Any thoughts? i also suspect a pcb but maybe because i'm elec biased[/b]

 

[ianmcd]

Run the HW and when the burner switches off, immediately turn the lever on the filling valve to the 9 oclock position (this stops the demand for HW and switches the boiler back to heating mode) and see what the display show2s if it is around 90 degrees then your Plate heat exchanger is blocked (most likely culprit) if this is not the cause come back aand let us know and we will advise on some other things it could be, and just for a note your boiler doesnt have the diaphragm you were going to change it utilises a motor but it is unlikely to be that

 

[mondo123]

I did the steps it shows 49
I then switched the water back to boiler and it displayed 22 again

 

[ianmcd]

does the CH flow pipe get hot while you run the HW ?

 

[mondo123]

the CH send return is hot
but its in combo mode at the moment as the ch tends to still work

the dhw send pipe is cool shall i turn to dhw mode only and check the ch pipes to ensure it cools accordingly?

 

[ianmcd]

best way to test it is when it is cold , if you can feel heat creeping into the CH system when only HW is selected then you need a service kit for your diverter valve but by the information you have given I would almost certainly say it is a slight blockage in the flue venturi which unfortunately I cant advise you how to check this on an open forum, but if I am correct this is easy enough sorted and shouldnt cost too much