Thermostat issue? Boiler not cycling fast enough.

paulski

Last year I had a cheap coil spring thermostat that the tenants kept turning to 80. I bought a digital thermostat from Chicago Controls that limits the upper temp  to 73. The problem is it would not cycle back on until the temp dropped below 60. I put the old thermostat back on a week ago but i'm having the same problem.



thx

nicholas bonham-carter

thermostat problem

the most popular thermostat with people here is the honeywell visionpro. it has settings for steam, and can have a remote sensor in the apartment, with the control panel somewhere else under your control. it also can have an upper limit set with a password.

why do the tenants turn up the setting on the thermostat? is some maintenance needed? check over your system to make sure that steam gets to all the inlet valves at the same time. if not, then you most likely have faulty main [not rad] vents, and have been paying the fuel company extra to force the air out. you may also have a bad location for the thermostat, and it is being satisfied by one hot radiator nearby, before the rest are warm.--nbc

JStar

RE

It may not be a thermostat issue. Could be a plugged up pigtail or pressuretrol.

paulski

Thermostat issue

After reading 2 of the steam books before last heating season. I insulated all my mains on the 3 year old peerless, wet return vapor system. I also moved the thermostat up stairs to a central stair area.  My fuel bills dropped $1000!!  Still, Fraternity boy tenants open windows when its to hot and jack up the heat when it's cold. It's hard to figure out when when they keep touching the temp so I put in the upper limit thermostat. Maybe this stopped the heat waste on one end but exposed the temp drops.    The system puts out good heat when it cycles on.

paulski

trouble shooting

How do you trouble shoot these 2 issues?

Why would they cause the boiler not to cycle on often enough? 

thx

nicholas bonham-carter

temperature swings

i don't know what percentage of fuel use you have saved so far, but in my case, it was 30% adjusted for degree days from the pre-new boiler year to the second season, when all the bugs were out of the system.

if the tenants are opening the windows in the swing season, then it must be too hot, and if they jack up the thermostat later, then they are cold. this points towards swings in temperature. is the anticipator of the thermostat set properly for steam? 

is the upstairs hallway really the best location for the thermostat? often, hallways are somewhat unheated, and therefore the system may run too long untill that area picks up enough heat. the hallway may be last to lose heat as well.

try to find out why the boiler is not keeping the temperature up, first determine which part is not firing when needed.

to determine whether the thermostat is the problem, use a jumper wire on the boiler to see if it will fire. if it does not, then there could be slow returns which could keep the waterline too low until the water comes back.

a digital indoor-outdoor thermometer with sensors will remember the high and low temperatures in several areas and you can see where a new visionpro thermostat sensor location would be. i use a colder area, but keep the setting at 65 deg.--nbc 

JStar

RE

The boiler may run up to pressure, shut down on the pressuretrol, and the blocked pigtail won't let the steam release the pressuretrol, causing it to stay off for longer than usual amounts of time.

nicholas bonham-carter

off on safety?

you could use the jumper wire on the thermostat to see if the boiler will run uninterrupted until the steam arrives at the radiators. if it is short-cycling, or rising above a few ounces while venting, then you need more venting, or a smaller boiler.

this makes me wonder why the mfgs [M-M, and honeywell] of the safety devices and pressure controls we have on steam boilers do not incorporate an led into each one, to show from across the room when they are activating and preventing the boiler from running.

a tell-tale on the gorton #2 vent would be nice as well, showing when venting had stopped.--nbc

paulski

Bad venting?

I found out  that because the boiler dosn't heat  enough, that the upstairs tenants are using space heaters. This statisfies the thermostat and the furnace does't turn on. I pushed up the temp and watched the system cycle for 25 minutes.... 2 of the 4 mains and rads heat up in 8+ minutes, 1 partially heats one dosent heat. I have Hoffman 75H main vents. Also, one main returns is sagging over an interior cement wall which was  notched slightly.   

I ordered 4 Gorton # 2. I'll add these in front of the Hoffmans .. after I boil them in vinegar.  I'll jackhammer the notch lower to remove the sagging pipe which bangs on start up and only partially heats. After this i'll check the system again .. I'll do all this Nov 19th  .. this weekend i'm take the boys bow hunting!  I'll up date before Thanksgiving. 

paulski

Bad venting?

I found out  that because the boiler dosn't heat  enough, that the upstairs tenants are using space heaters. This statisfies the thermostat and the furnace does't turn on. I pushed up the temp and watched the system cycle for 25 minutes.... 2 of the 4 mains and rads heat up in 8+ minutes, 1 partially heats one dosent heat. I have Hoffman 75H main vents. Also, one main returns is sagging over an interior cement wall which was  notched slightly.   

I ordered 4 Gorton # 2. I'll add these in front of the Hoffmans .. after I boil them in vinegar.  I'll jackhammer the notch lower to remove the sagging pipe which bangs on start up and only partially heats. After this i'll check the system again .. I'll do all this Nov 19th  .. this weekend i'm take the boys bow hunting!  I'll up date before Thanksgiving. 

paulski

Draining water

Before I turned up the heat .. as posted above and trouble shot the system ... I drained the dirty water .... while doing this the furnace turned on for about 5 minutes and shut of ... Why would it do this?   I haven't noticed other short cycling issues although I'm not sure.