Buderus

J Matthers_2

I have been looking at the GB142-24 as back upfor a geo system and for some additional space. The other day someone pointed out the Lochinvar Knight 80 as a well made unit modulating in the same range for about 25% less $$. unit will not be used for DHW just a few IFR zones and to boost the geo on sub 20* days. It will also provide total backup if the geo goes down at all. Should I spend the extra $$?

Thanks

jeff_51

I'm not familiar with the Lochinvar

but the Buderus is a dream. With the infinetley modulating burner it is very versitale. Perfect for low or high demand

Joe Brix

call me cheap

but for a backup system that won't be used much why are you getting an expensive complicated boiler? Wouldn't a regular 80% boiler suffice. I'd hate for a boiler to sit idle for 11 months of a year then won't start because some electronics board went bad. Maybe invest is a simple wall hung direct vent boiler since I assume you don't have a chimney.

J Matthers_2

It is not for just backup, it will be handling four IFR zones that I am taking off the Geo. When the geo was installed we comprimised on the heating side because i didn't want to oversize the cooling side. For the last two years I have provided additional heat when needed (below 20*)from a loop off my Takagi to a heat exchanger. I have since improved third floor space and a loft area over the garage demanding another 30,000 btuh, too much for the geo to provide. This new unit will be suppling anyware from 25,000 to 80,000 btuh all heating season. Additionally, while I drive a gas guzzling SUV to haul my kids around, I made a big effort to build a house that burned as little fuel as possable. To install anything but a high efficancy modulating unit wouldn't seem right.

I do have a chimmny but not one I could use to vent a direct vent boiler. The flue has too many angles in it.

J Matthers_2

Has anybody installed one of these Knight 80's?

Joe@buderus_2

GB142

The GB142 can modulate as low as 25% of it's firing rate in 1% increments. Included with each GB142 is a piping manifold with union connections for the supply/return piping, relief valve, DHW supply/return tappings, 3 speed Grundfos boiler circulator, T & P gauge and shutoffs all packaged ready to be installed on the GB142. This adds cost to the GB142, but insures proper pipe connection, flow rate through the GB142 and ease of installation. Thanks,

Dave_22

Joe

Why does it have a 3 speed circulator to maintain flow? When would you change speeds? What if someone changed it by accident?