I just upgraded from a Honeywell PA404A 1009 pressuretrol to a Honeywell L408J1009 vaporstat. The boiler is a Weil-McLain EG, and it's gas-fired.
I also upgrade the pressure gauge from a broken 0-30 PSI gauge to a Wika 0-20 oz gauge.
The vaporstat is currently set to break at 8 oz and make at 2 oz.
Not sure if this is relevant, but the house is about 1400 square feet, and steam is currently feeding to 6 radiators (house has 8, but I've temporarily removed 2 from rooms I'm renovating).
After hooking everything up, I tested the system. It took about 15-20 minutes for the system to warm up and the vaporstat to come into play.
Here's what I noticed once things were warmed up.
- According to the pressure gauge, the vaporstat breaks as set at 8 oz
- Once past about 7 oz, the gauge gets VERY jittery (worried this is going to harm the gauge over time)
- According the pressure gauge, the vaporstat makes at 5 oz; however, after the boiler kicks back on, the pressure continues to fall until about 2.5 oz (this would seem to indicate that the vaporstat is working as set, and the gauge reading is delayed, at least on the way down)
- All of the radiators heated up (so no need for more than 8 oz)
I timed the cycles, and am concerned that they are short (though this is totally gut feel, as I have no concept for how long the cycles should be). It took the boiler 1.5 - 2 minutes to get to 8 oz, and 30 - 45 seconds to drop back down to 2 oz. So - on for 1.75 minutes, off for 40 seconds, on for 1.75 minutes, off for 40 seconds...
1. Is this short cycling? If so, approximately how long should the cycles be?
2. If this is short cycling, what can I do to fix it?
3. How can I prevent the pressure gauge from getting jittery?