Grundfos pump on baxi 105e combi

[striker]

Bit of advice needed from the boilerists please, my baxi 105e had the low pressure led flashing and intermittent hot water. General opinion was to replace pump and automatic air valve. This made sense as the pump's been squeeling for a while.
Anyway changed both today, seems to have done the trick!
When I ordered the pump I paid a bit extra for the grundfos as the original has lasted the 15yrs of the boilers life. However when it came it has 3 speeds and the original has one. I've set it at speed 3. Have I done the right thing?

 

[Seadog]

Diverter valve.

 

[Kayos]

Speed 2 is the set speed when the boiler doesn't have the lever

 

[striker]

Diverter valve.

Did that last year, or maybe the year before!
Just checked January 2022.

 

[striker]

Speed 2 is the set speed when the boiler doesn't have the lever

Thanks. I'll flick it over!

 

[striker]

Oh bu**er. Problem has come back. Might have to be the plate heat exchanger next or the micro switches on the diaphragm plunger pins, or dhw thermistor?
Open to suggestions though if anyone can help.
Problem is, water goes hot and cold, led above 60° flashes red (low pressure, pump failure or air in system). Boiler pressure steady 1.5bar.
Heating works fine, both diaphragms are operating pins to micro switches fine.
Turning the boiler off and back on works fine but still intermittent hot water.
Diverter valve recently changed and appears to be working ok.

 

[Seadog]

Possibly a switch fault, but, generally, they either work or don't.

 

[striker]

I've ordered a couple of switches and a dhw thermistor as they're cheap enough. Then if that doesn't work I'll clean or change the plate heat exchanger, then I suppose the PCB if that doesn't work. I have changed the PCB 8ish years ago.
Thanks for the advice seadog!

 

[striker]

It's like Triger's broom my boiler....

"I've had this broom 20yrs, it's had five new shanks and four new heads".