Finally diagnosed my heating problems to a bad Honeywell AQUASTAT L8148J (PHOTO 1) — the relay would click, but the circulator wouldn't turn on. Ordered a replacement and just installed (PHOTO 2). Turn on the system and…nothing. I physically close the relay and both the furnace and circulator come on as they should. I look over my wiring and saw I had the thermostat wire that should've been on T on W instead, correct it, turn it back on and still nothing. Figure it's the wire connecting the AQUASTAT to the zone valves, replace it, still nothing. Frustrated, I check online and find a video that points out I should see 24v between B1 and Z — I'm only seeing 17v. (PHOTO 3) (I tested B1 to both W and T, still only 17v). Question, do you think that A. I just got a faulty replacement or B. would the accidental wiring of the thermostat wiring cause damage that now prevents 24v from passing between B1 and Z. I'm close to calling in the professionals, but since I've come this far wanted to make sure I didn't overlook something. Any help/insight would be greatly appreciated. Thank you in advance. NOTE: I am reading 24v between ports 1&2 and 1&3 on my TACO power heads and the override moves freely.

I just had the (original?) gas valve replaced on a "68" Lennox gas furnace. The technicians tried to connect the tubing to the Vent connection but it was the wrong size coupling. They then mumbled something and re-capped the Vent on the new valve. Is the Vent connection and tubing required or recommended for this old gas furnace? Thanks for any info!