Zachary Smith
New Member
Hi,
My boiler started leaking water a few days ago, and after reading all the helpful posts I thought I'd post to get all of your educated thoughts. I also seem to have a unique boiler and thought everyone would be interested to see it. My heating guy has indicated that there is no likely ST fix to get through the winter and has started calculating what the new system should be.
House
- 1820's Federal with approx. 1/3 un-insulated. 1/3 w/ 1920s insulation, and 1/3 w/ 1960's insulation
- Windows are single pane with exterior and interior storms
- Around 4,000 sq feet
- Separate Propane instant HW heater
- Existing HW heating
- 49 ft Baseray Cast Iron Baseboard (370 BTU/hr/Linear ft)
- 35 ft Baseray Cast Iron Radiant Radiators (Inset, 20 inch tall, 5 inch deep, 187 sq ft at 240 BTU/Hr/Sq ft)
- 10.5 ft Classic 3 Tube Cast Iron Radiators (3 ft tall x 9 inches wide)
- 5 ft Smaller 3 Tube Classic Cast Iron Radiators (2 ft tall x 9 inches wide)
- 4 ft Tiny Classic Cast iron Radiator (1.5 ft tall x 4 inches wide)
Current Oil Boiler
- H.B. Smith 2500A/2500L 25 Mills
- 450,000 MBH
- Estimated circa 1960's
- Approx. 3 ftx 3ft x 4 ft tall
- See pictures
- Believe it's a universal pump/circulation
- 10 Taco zone valves for diff rooms, each feeding off main HW feed
- Believe it has an outside therm to adjust water temp
- Exhausts through existing chimney
- Dampness around base a week ago is now expanding and small trickle can be seen coming out of corrosion near base
Walked through the house this morning with my HVAC guy as well as someone who appeared to be from the wholesale heating supply company FW Webb. I am waiting for them to do the full calculations on my radiators and provide their full recommendation for boiler and size but had a few questions for everyone.
Due to the repeated advice on this and other forums that a heat loss calculation is REQUIRED to size the boiler properly, I asked if they would be doing that calc along with figuring out the radiation capacity. They replied that they could, but didn't need to.
I pushed again, citing the advice on here and my desire to prevent buying an overly large boiler and the resulting short cycling. They indicated that I have a large circulation system (see details above) and a huge amount of radiators that would require a large boiler, the boiler size will be determined by that rather than by heat loss.
Questions:
1. My guy refused to give a rough estimate until he did calcs but the FW Webb guy offered a prelim size guess of around 375,000-400,000 MBH. The current boiler is 450,000 MBH and doesn't seem to short cycle. My house is very large (>4,000 sq ft), very old (1820), very drafty, but does this seem really large?
2. They mentioned Buderus as a possible brand, and think they may have mentioned the G315 series. Does anyone have experience with those or thoughts? I want an oil unit that could be switched to gas in the future and prefer reliability to super efficiency.
3. Is it possible they are right that the system can be sized just based on the current radiators? I trust my HVAC guy to a ridiculous degree but their response doesn't jibe with the thoughts on this board. He indicated that my system has to move/heat so much water that short cycling shouldn't be an issue.
4. What is the benefit to my heavy cast iron baseboards vs regular base boards. He indicated they actually throw off less BTUs but radiate the heat better???
My boiler started leaking water a few days ago, and after reading all the helpful posts I thought I'd post to get all of your educated thoughts. I also seem to have a unique boiler and thought everyone would be interested to see it. My heating guy has indicated that there is no likely ST fix to get through the winter and has started calculating what the new system should be.
House
- 1820's Federal with approx. 1/3 un-insulated. 1/3 w/ 1920s insulation, and 1/3 w/ 1960's insulation
- Windows are single pane with exterior and interior storms
- Around 4,000 sq feet
- Separate Propane instant HW heater
- Existing HW heating
- 49 ft Baseray Cast Iron Baseboard (370 BTU/hr/Linear ft)
- 35 ft Baseray Cast Iron Radiant Radiators (Inset, 20 inch tall, 5 inch deep, 187 sq ft at 240 BTU/Hr/Sq ft)
- 10.5 ft Classic 3 Tube Cast Iron Radiators (3 ft tall x 9 inches wide)
- 5 ft Smaller 3 Tube Classic Cast Iron Radiators (2 ft tall x 9 inches wide)
- 4 ft Tiny Classic Cast iron Radiator (1.5 ft tall x 4 inches wide)
Current Oil Boiler
- H.B. Smith 2500A/2500L 25 Mills
- 450,000 MBH
- Estimated circa 1960's
- Approx. 3 ftx 3ft x 4 ft tall
- See pictures
- Believe it's a universal pump/circulation
- 10 Taco zone valves for diff rooms, each feeding off main HW feed
- Believe it has an outside therm to adjust water temp
- Exhausts through existing chimney
- Dampness around base a week ago is now expanding and small trickle can be seen coming out of corrosion near base
Walked through the house this morning with my HVAC guy as well as someone who appeared to be from the wholesale heating supply company FW Webb. I am waiting for them to do the full calculations on my radiators and provide their full recommendation for boiler and size but had a few questions for everyone.
Due to the repeated advice on this and other forums that a heat loss calculation is REQUIRED to size the boiler properly, I asked if they would be doing that calc along with figuring out the radiation capacity. They replied that they could, but didn't need to.
I pushed again, citing the advice on here and my desire to prevent buying an overly large boiler and the resulting short cycling. They indicated that I have a large circulation system (see details above) and a huge amount of radiators that would require a large boiler, the boiler size will be determined by that rather than by heat loss.
Questions:
1. My guy refused to give a rough estimate until he did calcs but the FW Webb guy offered a prelim size guess of around 375,000-400,000 MBH. The current boiler is 450,000 MBH and doesn't seem to short cycle. My house is very large (>4,000 sq ft), very old (1820), very drafty, but does this seem really large?
2. They mentioned Buderus as a possible brand, and think they may have mentioned the G315 series. Does anyone have experience with those or thoughts? I want an oil unit that could be switched to gas in the future and prefer reliability to super efficiency.
3. Is it possible they are right that the system can be sized just based on the current radiators? I trust my HVAC guy to a ridiculous degree but their response doesn't jibe with the thoughts on this board. He indicated that my system has to move/heat so much water that short cycling shouldn't be an issue.
4. What is the benefit to my heavy cast iron baseboards vs regular base boards. He indicated they actually throw off less BTUs but radiate the heat better???