Sizing Grant Vortex Oil Fired Cond Boiler

[Asif Qureshi]

I am trying to self assess the new Condensor Boiler sizing for a 18 yrs old built. It's oil fired Firebird Reillo has packed in. It was a 19- 35KW rated non condensing boilerhouse unit.
This is a large 3000sqft property with ground and first floor.
Considering the first floor with 5 beds 3 loos and 15 rads , My calculated estimate is 15KW
The ground floor has 12 rads and estimated 20KW heating load.
The property has already got S planned system with 3 Motorized valves and Honeywell planned hot water/ selective upper and lower floor heating selection with room stats for each floor.
I need advice about sizing the Grant Vortex Condensor Boiler which is the brand I want.
Would you go for a 26-36Kw (90-120) or 36-48(120-155) Model ?? Considering the split heating / full or half house load and the appropriate size of boiler.
From expert opinions I acquired , Condensor Boiler should be appropriately sized and should not be over sized...
It's really about choosing which one to go for ........ and the logic behind it if I may ask for future knowledge.
Thanks
A Q

 

[SimonG]

Get your installer to spec it.

Especially as last month this was your house, now you are wording it as though you are doing this for a customer!

 

[Asif Qureshi]

Thanks for correcting me.
I want your expert advice.

 

[Best]

You need it signed off for warranty, so better getting a heating installer in at this stage to steer you to make the right decisions on boiler size etc.
Full heating load will need full size boiler.

 

[ShaunCorbs]

Thread closed