Barry Rogers
New Member
Hey Gang,
Sorry for the length of the post. I have a couple issues and I have posted on other sites before and realize that there is a lot of info needed to paint a picture for someone. I can grab a few pics also if needed.
I'm troubleshooting an issue that is a little out of my comfort zone. Long story short that was suppose to be setup and working on arrival and now I'm stuck in the arctic with an unreliable heating system and no boiler mechanics for many miles. I am working on a Heil oil fired boiler that is working like a charm but has a few issues that are causing it to be unreliable and inefficient. The boiler basically is short cycling and the post purge is running for too long at -35C and has no adjustment with the aquastat on the low temp cut-in. My goal is to increase the time between cycles on/off and decrease post purge time. Hopefully making the unit a bit more efficient.
Here are the details on the boiler and unit:
-Heil HMR model boiler with 4 zone valves\thermos for 4 in-floor heating loops in a 3 BR 2000 sq.ft living unit.
-Beckett burner AFG model and honeywell controller(R7184B) are connected to a low pressure cut-off and and low water cut-off and on to the 120VAC junction box. (no issues there but I'm guessing the Honeywell controller box is underused and my be able to eliminate some useless parts.
- Between the low pressure switch and the burner controller box is a Honeywell aquastat L6081A. I think the white wire should be connected through the unit to allow the aquastat to control the connection on the white(neutral) wire. But I'm not sure and from what I see and read a lot of people jump the White(neutral) together and run the aquastat only off the high temp setting but I do not want to touch this and risk frying my only aquastat. Also I guess that is why my boiler fires when the temp drops 20F below the high time setting. I should mention I have played with the Diff and it is set to 20-25 now. If it is lower it seems the boiler never has a chance to cycle off.
- the glycol is pushed with a pump continuously and a wild loop is in place for when zone valves are not open. Odd thing is it seems like it was run into a Honeywell transformer (RA89 A 1116) which now is bypassed and the wire coming from 120VAC junction box on the wall is removed from the transformer and marretted to the wires running to the pump directly powering the pump. (wondering if this is damaging the pump and if I should just tidy up the wires and add a switch to make it .....safer?) from that transformer was a low voltage wire that appeared to be powering the zone valves and/or slab sensors? not sure but there are 4 other low voltage wires that go into the wall that are not powered because the transformer is no longer in use. The zone valves for the thermostats are powered by a separate very basic transformer block similar to a door bell type. The thermostats are powered by a second one next to it. I'm guessing I can remove that Honeywell transformer and tidy up the wire mess there once my 2 main issues are dealt with.
- the sidewall power venter and damper is powered by a Proving switch or pressure switch Model K07003 (computer board inside says B01131 Dettson) This is the unit that should help adjust the post purge time but I cannot find any info on it or anything inside to adjust like dip-switches, jumpers, dial pots, etc. So I'm assuming that it would need to be replaced but I do not want to order anything until I'm sure it will work. I can not risk having this heating unit down for very long in the harsh arctic temps.
Prob#1 is the sidewall vent has a post purge time of 5.5 min and is pushing all the heat out of the mech room. At -40c that is cooling the room after every cycle. I can not find any information on the unit that would adjust that time. Perhaps it can't be adjusted and needs to be replaced with one that can.
Prob#2 the boiler is short cycling. The Boiler with fire up no problem, run for 3 min and shutdown no problem while the sidewall vent runs another 5 min. Problem seems to be a couple things like the heat loss and cold glycol returning from the heat loops into the unit. But one issue I cannot fix or adjust is the cut-in temp on the aquastat. I can adjust the high temp cutoff which is at 160F but the cut-in low temp seems to always be 20F below the high temp setting. The low temp know has no effect on the boiler but I can hear the clicking near the proper temp compared to the gauges. I believe the aquastat is not wired properly and the low temp adjustment is bypassed. The black wire is run into the aquastat but the white wire is jumped and connected with a marrette. Another problem is that fact that the infloor heat has no 3-way mixing valve but that issue was identified and is on order. The boiler temps have been reduced slightly until the part is installed.
The issues I need help with are:
Issue#1 - Info on the pressure switch and how to adjust post purge time or a replacement unit that will let me reduce the time to 15-30sec.
Issue#2 - How to properly wire the aquastat or adjust the cut-in low temp to allow a larger diff between start up and shutdown times.
Thanks all for any help. These forums are great.
Sorry for the length of the post. I have a couple issues and I have posted on other sites before and realize that there is a lot of info needed to paint a picture for someone. I can grab a few pics also if needed.
I'm troubleshooting an issue that is a little out of my comfort zone. Long story short that was suppose to be setup and working on arrival and now I'm stuck in the arctic with an unreliable heating system and no boiler mechanics for many miles. I am working on a Heil oil fired boiler that is working like a charm but has a few issues that are causing it to be unreliable and inefficient. The boiler basically is short cycling and the post purge is running for too long at -35C and has no adjustment with the aquastat on the low temp cut-in. My goal is to increase the time between cycles on/off and decrease post purge time. Hopefully making the unit a bit more efficient.
Here are the details on the boiler and unit:
-Heil HMR model boiler with 4 zone valves\thermos for 4 in-floor heating loops in a 3 BR 2000 sq.ft living unit.
-Beckett burner AFG model and honeywell controller(R7184B) are connected to a low pressure cut-off and and low water cut-off and on to the 120VAC junction box. (no issues there but I'm guessing the Honeywell controller box is underused and my be able to eliminate some useless parts.
- Between the low pressure switch and the burner controller box is a Honeywell aquastat L6081A. I think the white wire should be connected through the unit to allow the aquastat to control the connection on the white(neutral) wire. But I'm not sure and from what I see and read a lot of people jump the White(neutral) together and run the aquastat only off the high temp setting but I do not want to touch this and risk frying my only aquastat. Also I guess that is why my boiler fires when the temp drops 20F below the high time setting. I should mention I have played with the Diff and it is set to 20-25 now. If it is lower it seems the boiler never has a chance to cycle off.
- the glycol is pushed with a pump continuously and a wild loop is in place for when zone valves are not open. Odd thing is it seems like it was run into a Honeywell transformer (RA89 A 1116) which now is bypassed and the wire coming from 120VAC junction box on the wall is removed from the transformer and marretted to the wires running to the pump directly powering the pump. (wondering if this is damaging the pump and if I should just tidy up the wires and add a switch to make it .....safer?) from that transformer was a low voltage wire that appeared to be powering the zone valves and/or slab sensors? not sure but there are 4 other low voltage wires that go into the wall that are not powered because the transformer is no longer in use. The zone valves for the thermostats are powered by a separate very basic transformer block similar to a door bell type. The thermostats are powered by a second one next to it. I'm guessing I can remove that Honeywell transformer and tidy up the wire mess there once my 2 main issues are dealt with.
- the sidewall power venter and damper is powered by a Proving switch or pressure switch Model K07003 (computer board inside says B01131 Dettson) This is the unit that should help adjust the post purge time but I cannot find any info on it or anything inside to adjust like dip-switches, jumpers, dial pots, etc. So I'm assuming that it would need to be replaced but I do not want to order anything until I'm sure it will work. I can not risk having this heating unit down for very long in the harsh arctic temps.
Prob#1 is the sidewall vent has a post purge time of 5.5 min and is pushing all the heat out of the mech room. At -40c that is cooling the room after every cycle. I can not find any information on the unit that would adjust that time. Perhaps it can't be adjusted and needs to be replaced with one that can.
Prob#2 the boiler is short cycling. The Boiler with fire up no problem, run for 3 min and shutdown no problem while the sidewall vent runs another 5 min. Problem seems to be a couple things like the heat loss and cold glycol returning from the heat loops into the unit. But one issue I cannot fix or adjust is the cut-in temp on the aquastat. I can adjust the high temp cutoff which is at 160F but the cut-in low temp seems to always be 20F below the high temp setting. The low temp know has no effect on the boiler but I can hear the clicking near the proper temp compared to the gauges. I believe the aquastat is not wired properly and the low temp adjustment is bypassed. The black wire is run into the aquastat but the white wire is jumped and connected with a marrette. Another problem is that fact that the infloor heat has no 3-way mixing valve but that issue was identified and is on order. The boiler temps have been reduced slightly until the part is installed.
The issues I need help with are:
Issue#1 - Info on the pressure switch and how to adjust post purge time or a replacement unit that will let me reduce the time to 15-30sec.
Issue#2 - How to properly wire the aquastat or adjust the cut-in low temp to allow a larger diff between start up and shutdown times.
Thanks all for any help. These forums are great.
