Humidity levels effecting boiler run times?

Kjmass1

So last year my 1 pipe steam system was running great. 19-20 min run times and constant, even heat. I haven't changed anything from last year with the home and recently I found the system to be running longer- approx 25 min run times. This is causing all the radiator vents to start to gurgle, hiss, clank, spit, etc when before the boiler would shut off before it got to that point. Needle on the 5psi gauge is bouncing a little bit, maybe .1psi. It's set to 1/2psi.

The only thing I can think of is that Nest updated their algorithm recently (the firmware updates are automatic which is annoying and scary).

The other is that I bought one of those whole house stand alone humidifiers. The house last winter was really dry- 15% at some times. This humidifier is keeping the house at 30%. I know humidity should make it feel warmer, but how does that effect the thermostat and does boiler need to work harder?

Anything else I could be missing? It feels like the radiators are heating up the same as last year, but it obviously isn't satisfying the thermostat fast enough.

Thanks
Kevin

Jamie Hall

The humidity -- at least at that level -- is unlikely to make much of a difference, although in theory it might a small difference.

The Nest, on the other hand... I wouldn't trust one as far as I could throw it, and that's not very far. Have you tried a real thermostat?

Kjmass1

I've started to look in to the ecobee3 to replace the Nest but haven't pulled the trigger just yet.

I did a quick comparison of last years data and I am using the exact same amount of boiler hours to heating degree days, .12hrs/HDD. So essentially I'm running cycles 5 minutes longer but less cycles. Well I can't complain for the system not being consistent.

I'm effectively running @ 1.8 CPH (Nest can't sent CPH), 13 cycles per day.

I did institute a 3 degree setback at night with a slow 1 degree per hour recovery in the morning. I hear the vents hissing throughout the day so it's not just coming out of setback.

A vaporstat would be nice to have or a 20 min time limit on boiler burns like the ecobee offers would solve the problem.

Fred

Have you made sure your main vents are all working? Maybe one is stuck closed, making it harder for steam to move through the main and causing the system to vent through the rads. Also, have you cleaned the pigtail the Pressuretrol is mounted on?

Kjmass1

Thanks Fred. Steam seems to get to the mains normally and I can hear the radiator vents close up. I'll check the pigtail tonight and make sure main vents are clear.

System is quiet until 20 minutes at which point the pressure starts to cause some noise until it shuts off at 25 min.

I didn't have the boiler looked at this year...kept pilot light on all summer and did the normal flushing out the dirty water. Any other maintenance that should have been looked at?

Fred

Oil fired burners probably should be checked/cleaned/adjusted every year. NG, probably less critical but not a bad habit to get into.
Is there any accessable software activity log on the Nest that may tell you if/when updates were performed? That might be a clue. Is there a reset button on it that restores the factory settings/software, if you find it has been updated?

Kjmass1

It's a NG burner. I will say it does seem like when the boiler turns off, the "thump thump" of the gas cutting out is a bit louder than I remember it last year- only because the living room is above the boiler so it seems to stick out more than usual.

You can see when updates were applied and Nest lists all the changes on their site. There was one that stood out to me but it said it didn't apply to radiant systems but I imagine they are constantly tweaking things which is good and bad. I might try a full reset and see if that changes anything.

I'm tempted to throw the old honeywell back on there.

Fred

I use a Honeywell 7000 series digital thermostat. It works fine. I've seen lots of controversy over how compatable the Nest is with steam.

Gordy

Jamie Hall said:

The humidity -- at least at that level -- is unlikely to make much of a difference, although in theory it might a small difference.

The Nest, on the other hand... I wouldn't trust one as far as I could throw it, and that's not very far. Have you tried a real thermostat?

Who would have ever thought people could be so infatuated with a thermostat....

Gordy

EzzyT

2 years ago I did the plumbing and some heating on 4 houses on this one block that where all remodeled by the same General contractor and a/c was added to theses house but the steam systems where left intact, just had to move some radiators upgrade main and radiator vents. GC had a great idea and sold all 4 home owners on putting in Nest thermostats and had the electrician install them. Well when winter rolled around last winter I got a call from GC and homeowners screaming and yelling at me that there having issues with there heat. I go take a look and determined that the brand new Nest thermostats where the cause of the issues, but to confirm that Nest thermostats where the cause I swamped them out with honeywell pro 4000 and had them in for over a week to see if that solved the issue, sure enough it did and i got yelled at some more by the GC for making him look bad on his stupid up sell