HEP2O Underfloor heating

[gordonhayward15]

I have a HEP2O system installed 8 years ago and has worked fine. 6 months ago I installed a new boiler, but in a different location - in the bathroom directly above, and now my HEP2O system hardly works. It seems to warm about one tenth (maybe less) of the floor but the rest remains cold. I have tried balancing all the radiators but this has not improved matters. Can anyone suggest a solution please?
If I close down all the radiators it does work, but then the rest of the house does not heat up.
Thanks Gordon

 

[ShaunCorbs]

Did you install the boiler

Also same output as your last boiler

Could be air in the loops that need purging

 

[Riley]

I'd be thinking air but why didn't installer fix it

 

[gordonhayward15]

Shaun, thank you. It was installed by B Gas and is a similar size to previous boiler. I will try, again, to rid any air from the system. Gordon

 

[gordonhayward15]

thank you, I will try, again, to get rid of air. Gordon

 

[SimonG]

What boiler did you have previously? and what boiler now. Did the old boiler have an external, to boiler, pump and the new one an internal pump?