Baxi 105e instant combi- intermittant DHW

[IDCHAPPY]

This old chestnut again by the looks of it, customer complains of intermittent hot water so i called Baxi and they recommended a new DHW sensor.
I ordered one up, and finally got it to see/change it(they work during the day so it's another night time only visit 🙁 ).

Fired it up and it seemed fine and customer seemed happy, roll on the next day and they are saying they are still having a problem so back out i go.

The preheat/temp control dial is right down so i turn it up mid way. They turn on the tap and I'm getting circulation round the heating circuit when it's fired up, even when it's on hot water only and the 60 C light if light(which is pump fault according to the manual). Both micro switches appear fine as do the pins pushing them so I presume it must be an error with the actuator on the 3 way?

Are these boilers crap? :lol:

Thanks in advance chaps :smoking:

 

[Ermintrude]

This old chestnut again by the looks of it, customer complains of intermittent hot water so i called Baxi and they recommended a new DHW sensor.
I ordered one up, and finally got it to see/change it(they work during the day so it's another night time only visit 🙁 ).

Fired it up and it seemed fine and customer seemed happy, roll on the next day and they are saying they are still having a problem so back out i go.

The preheat/temp control dial is right down so i turn it up mid way. They turn on the tap and I'm getting circulation round the heating circuit when it's fired up, even when it's on hot water only and the 60 C light if light(which is pump fault according to the manual). Both micro switches appear fine as do the pins pushing them so I presume it must be an error with the actuator on the 3 way?

Are these boilers crap? :lol:

Thanks in advance chaps :smoking:

Have u checked diaphragm and secondary hex for cleanliness? I had one in a pizza establishment where by the thermister in pcb was goosed!

 

[IDCHAPPY]

Have u checked diaphragm and secondary hex for cleanliness? I had one in a pizza establishment where by the thermister in pcb was goosed!

I was thinking about the plate hex, the things rammed in a cupboard though so i was hoping it may be something simple ::smile5:

 

[Ermintrude]

Plate in and out in under 130 seconds!

 

[diamondgas]

What temp rise you getting on the hot? Flow rate is?

This time of year hot water is going to be a lot colder ... However if it's backing down the heating then it'll be either phex or diverter faulty I'd guess 🙂

 

[jonnyswamp]

If your getting circulation around the heating circuit (when heatings off and a hot tap is run) the diverter valve needs looking at/replacing, its not sending all the primary water to the plate heat exchanger, so not heating the hot water enough
Have had a few Baxi's like this

 

[TBServices]

As above. Beware also, that if the diverter is passing on these, and you leave the preheat on, the boiler will just run and run

 

[sputnick]

As already said could be diveror I had exactly same problem, stripped it and found loads of gunge around the spindle with rubber stop on inside the valve. Cleaned if reassembled and working fine. Beward don't let water get everywhere ie on pcb if you do this

 

[arran197]

Replace or strip and clean the diverted valve and phex. Most likely the phex will be ok if cleaned with some x800 or such like but the diverted may well need replacing.

 

[IDCHAPPY]

Thanks guys, the guy hasn't got back to me yet, which reminds me, i still have to bill him of the investigations and sensor... 🙂