Downfiring Thermoflo/GSA 150 - anyone an agent?

Si_zim

Hi

Based on another thread I am convinced my boiler is way too big. It's 125kBTU NET rated (392sq ft EDR) and I only have 242ft of Steam rads (58kBTU) and will have probably another 35kBTU of hot water baseboard (when done with an extra project) for a total of 92kBTU.

I read lots of threads saying it's not such a good idea to downfire but was wondering if anyone had experience with this boiler? Seems I should be running 25% less capacity - but that sounds like it may cause combustion issues.

I note in the manual (<a href="http://www.heatinghelp.com/files/posts/9594/Thermoflo%20GSA-150%20Boiler%20Manual.pdf">http://www.heatinghelp.com/files/posts/9594/Thermoflo%20GSA-150%20Boiler%20Manual.pdf</a>) that a smaller orifice can be fitted for high altitude... wonder if that would help. I am in NJ - not far above sea level... but I would hope this could reduce firing intensity without messing up the mixture much. (2.45mm vs 2.30mm may not make much difference)

Any insight or other suggestions would be appreciated

Si_zim

Orifice sizes are on pg 7 of the manual

Says for US high altitude use to contact local supplier for details... so not sure what other orifice sizes there are. (2.30mm for >2000ft in Canada though)

Thanks again

kevin_58

gsa 150

I believe a thermaflo is the same as a union steam or williamson basicly a weil mc lain generic. If that is the case a 150 and 125 btu have the same block so you can change burner tray to a 125 000 tray and lower to 325 sq ft of steam. also when you add a baseboard loop off boiler you do not add it to size of boiler you only use  boilers pickup factor.

Si_zim

Good news

Thanks- that's some good news. Anyone in Northern NJ have the parts and up for the job?

Sounds like boiler is still too large if the hydronic baseboard can be absorbed in the pickup but every bit helps to reduce pressure cycling and waste



Thanks again



PS: Boiler is actually branded Genesis GSA150 but I believe it's a Thermoflo/generic Weil McLain

EzzyT

northern nj?

where in northern nj are you located? i could come and take a look at what can be done

Si_zim

In Rutherford

Message me if you cover this area and want to quote, I have a few other things I want to do with the heating also (but I will not do those until summer time)

Anyone feel free to comment if this is not worthwhile - hoping swapping the burner tray out will not be invasive and too steep - but I think current setup is way oversized so anything to reduce it will only help (this will be almost 20% reduction which is pretty good)