Ferroli Boiler No hot water

[CRS]

Good evening folks,
I have a Ferroli C24 combi LPG boiler, i have had to take it apart to clean the heat exchanger as there was no water flow, but there was CH water flow. once i put it back together i now have water flow but it's not hot unles the CH is going but then its only warm. i did take the HW senor off and i cleaned a white residue off that i thought was a residue from the copper pipe but now i am wondering if it was not a gel for the sensor. It may be a simple sensor replacement but before pay for the Ferroli spanish plumber to come and shrug his shoulders like he normally does i could do with some suggestions. the CH and the HW go into different sides of the heat exchanger and from what i can see there is no diverter valve if that helps
Thanks for any help.

 

[ianmcd]

The white residue is heat sink paste it helps to transfer the heat to the sensor, wouldnt worry too much that you have cleaned it off it just wont be as accurate it wont damage anything

 

[CRS]

Just an update,
replaced flow switch and HW sensor and still no hot water, anyone any ideas?
Thanks

 

[dcawkwell]

Just an update,
replaced flow switch and HW sensor and still no hot water, anyone any ideas?
Thanks

Diverter valve assuming the boiler fires when you turn the tap it
a diverter valve problem.

 

[ianmcd]

your boiler doesnt have a diverter valve, more information please, do you have central heating / does the boiler do anything when you run the tap , Fan run ? pump run ?

 

[CRS]

Hi Ianmcd
when the tap is running there is nothing from the boiler, no firing up or pump running just running water no error flashes coming from the boiler.
the central heating works fine comes on and turns off when told to do so. i am able to get warm water when the central heating is on but i guess that will be because the the boiler is fired up for the heating, the heating does not stop once the HW tap is running.
hope this helps.
Cheers

 

[ianmcd]

its something to do with your flow switch, basically when your boiler is running on CH the pump takes the heat to the radiators, when you open up a HW tap the pump stops and the flame increases and the water that comes out of your tap runs through the main heat exchanger and picks up its heat, as the heating is working it is something to do with the DHW flow switch

 

[CRS]

just to let you know ianmcd, i just wiggled the CH sensor and then turnde on the hot water and would you belive it the boiler fired up. the water is not as hot as i would like but its a start. cheers for help.