Vaillant ecofit pure keeps erroring

[ianmcd]

According to manual, there need to be a TRV between the main pump and boiler return,

Do you not mean an automatic By-pass valve ? why would you fit a TRV ?

 

[Bl888]

Do you not mean an automatic By-pass valve ? why would you fit a TRV ?

Not sure what I’m looking for here tbh. Does it look like a copper colour thing that your can turn there nob?

 

[rbranco]

Do you not mean an automatic By-pass valve ? why would you fit a TRV ?

Sorry I meant ABV

 

[Bl888]

Sorry I meant ABV

Is this the abv?

 

[Bl888]

Forgot to mention I also notice the grunfos alpha 2 pump body get really hot when it’s about to cut. Not sure if that’s a sign of anything

 

[rbranco]

Forgot to mention I also notice the grunfos alpha 2 pump body get really hot when it’s about to cut. Not sure if that’s a sign of anything

Yes that is the ABV, there are various different types.
What setting in the Alpha set on? I think that boiler should be on a constant speed to maintain flow rate though the boiler, if not it may overheat and trip out. The whole point of the ABV is to maintain boiler having a constant flow of water, especially when the valves close.

What is the flow temp on the boiler? Does the temp rise very quickly then trip?