I recently had a GV90+4 installed. It was somewhat of a winter emergency as my old Burnham boiler had started leaking and it was discovered that the cast iron portion was disintegrating.
I tried my best using fin tube measurements and old heating bills to downsize the boiler, since the plumber just wanted to install similar input. My old boiler was 198,000 BTU input and the new is 104,000 BTU, so I cut it almost in half. Still I'm observing short cycling and probably could have gone to the GV90+3.
I'm running on the internal circulator of the GV90+, with three zones using Taco zone valves. Zone 1 is 1st floor, zone 2 is second floor, zone three is indirect hot water with a SuperStor 60 gal tank. I was able to watch and measure some cycles on low single digit nights. With constant zone calls I saw cycles with 1-3 minute burns and 5-6 minute round trip. The IBC is programmed for a fixed 20F drop. I verified that there was no way I could change this with Weil-Mclain (had to pretend to be a plumber or they wouldn't even talk to me). So if I had Max temp set to its high limit of 200F, the boiler would fire until that was hit, then flame would shut off. Boiler temp then falls to 180F (200-20), and purge/fire cycle then starts up. I estimate this would give me 10-12 cycles of suboptimal burn per hour.
I was able to manually simulate a 50F swing by setting the Boiler max temp to 170 so that it's cycle would start at 150, then after burn started, I would set the max temp to 200. For the few cycles I observed doing this, I got 5-8+ minute burns and 18-20+ minute cycles. This would be much more ideal, with 3-4 cycles per hour I'm assuming.
The boiler's max temp low limit is 140F, so I think I could give something like the Intellidyne HW+ maybe 60F to play with safely, and I like that unit's simple setup. My questions are: Is the Intellidyne HW+ still available, and secondly, the GV90+ has a built in IBC that is doing a few things, like running a bypass curculator to protect the cast iron heat exchanger for example. I'm not sure how to wire the HW+ in, or if it's even possible to. If any other details about my setup are needed, let me know. Thanks in advance.
I tried my best using fin tube measurements and old heating bills to downsize the boiler, since the plumber just wanted to install similar input. My old boiler was 198,000 BTU input and the new is 104,000 BTU, so I cut it almost in half. Still I'm observing short cycling and probably could have gone to the GV90+3.
I'm running on the internal circulator of the GV90+, with three zones using Taco zone valves. Zone 1 is 1st floor, zone 2 is second floor, zone three is indirect hot water with a SuperStor 60 gal tank. I was able to watch and measure some cycles on low single digit nights. With constant zone calls I saw cycles with 1-3 minute burns and 5-6 minute round trip. The IBC is programmed for a fixed 20F drop. I verified that there was no way I could change this with Weil-Mclain (had to pretend to be a plumber or they wouldn't even talk to me). So if I had Max temp set to its high limit of 200F, the boiler would fire until that was hit, then flame would shut off. Boiler temp then falls to 180F (200-20), and purge/fire cycle then starts up. I estimate this would give me 10-12 cycles of suboptimal burn per hour.
I was able to manually simulate a 50F swing by setting the Boiler max temp to 170 so that it's cycle would start at 150, then after burn started, I would set the max temp to 200. For the few cycles I observed doing this, I got 5-8+ minute burns and 18-20+ minute cycles. This would be much more ideal, with 3-4 cycles per hour I'm assuming.
The boiler's max temp low limit is 140F, so I think I could give something like the Intellidyne HW+ maybe 60F to play with safely, and I like that unit's simple setup. My questions are: Is the Intellidyne HW+ still available, and secondly, the GV90+ has a built in IBC that is doing a few things, like running a bypass curculator to protect the cast iron heat exchanger for example. I'm not sure how to wire the HW+ in, or if it's even possible to. If any other details about my setup are needed, let me know. Thanks in advance.
