SOLVED (with NEST Thermostat!): How to limit temperature swings with radiators? archived

most thermostats have a "7 degree" differential, some have more. "bumping" the stat is a "quick fix", set it up 2 to 3 degrees and leave it alone. When you "bump" you are wasting(?)
your time and energy!!!!

What does a "7 degree differential" mean in layman's terms (and how can I avoid it in the future!)
We are comfortable keeping our house on the cool side most of the time but there are occasions (like when the sun goes behind clouds or a cold front comes blowing in) that we simply need more heat. It shouldn't be so hard...

The Nest is supposed to have a killer thermometer and be very very accurate. Depending on your system though you might need some electrical work done. It says it is compatible with a non-powered 2 or 4 wire system so just heat or heat and AC but no power but there are reports that it draws power when those systems are on and if it runs low on juice it does quick short cycling of your heat on and off to get its juice.

I LOVE the look of the Nest and I trust its set it and forget it nature. I'm a little less sure about the sensor to tell if you are home as ours would be downstairs so if you hang out upstairs all day it might leave you in the cold. I believe they are sold out until March or so ... but if it does work with minimal changes to our system then I might have to spend the $250 ... or maybe it is just a cool toy kinda thing and turning the heat up and down by hand isn't such a bad thing?

KMK,
I've always lived w/ steam, so from here I'm a bit foggy. Start by using a thermometer to check the actual temp in each room. Check room temp at the thermostat. Some rooms may off by quite a bit. Check for heat reaching each radiator. Check room temp when heat just comes up in morning and again later in day. We have one radiator that's so far from boiler that it only gets hot when system goes from night mode to day. The system is on long enough that steam pushes to that point after a long run.
In short, try to diagnose or find pattern(s) of heat imbalance.
Hot water systems have bleeder valves. These are used to remove air in the system. When was last time you did yours?
GL

We bleed them every year!
I am thinking there may be a problem with our thermostat. It is a 10 year old programmable model. I have noticed a couple of times it sort of blinked. Maybe it is an easy solution and requires a simple replacement. (We have been here 16 years and I don't remember our house ever having so many temperature extremes. But then even the exterior temps have been extreme as of late!)

kmk said:

We bleed them every year!
I am thinking there may be a problem with our thermostat. It is a 10 year old programmable model. I have noticed a couple of times it sort of blinked. Maybe it is an easy solution and requires a simple replacement.

That's why I suggested testing accuracy of readings at the thermostat. Existing therm probably has battery back up- replace those first.

We have found the culprit - it was absolutely the 9 year old thermostats.

We now have installed two of the absolute COOLEST, most fantastic thermostats ever made! The house is a dream. The thermostats even have light and humidity sensors and the know when the sky gets dark that they may need to call for heat. It also taught itself the length of time needed to reach desired heat levels and , accordingly, it begins to heat the house that many minutes before I need it to be warm. Did I mention that they are web-enabled and I can check and change the thermostat from my iPhone?!

http://www.nest.com/

Awesome I've been watching the NEST since it was a concept. Do you have steam radiators? Do you also have central A/C? I'm 95% certain they should work fine with steam boilers (no reason they shouldn't as long as the electric lead has the correct connections) but due to their cost I was wondering if it would be worthwhile with just heating. If it controls heating and cooling I think they are a no-brainer.

I have a few other friends who got theirs but I thought they were backed up and there was a delay on new orders ... did you order yours recently and get it delivered fairly quickly?

The whole NEST story is a really great one as well ... I think there are some amazing opportunities for innovation in many industries that have either just taken the status quo for granted or just are not bringing in fresh eyes to look at things from a new perspective. These kinds of innovations I think will really help the country on several fronts.

I got on their emailing list and placed an order as soon as they were available once again. I went ahead and bought 3!
We connected one in the downstairs thermostat location which controls our hot water radiators (heat - only had two wires). We connected a second in the upstairs hallway thermostat location which controls our upstairs-only central air conditioning (cool - had four wires.) THe neat thing is that online I can see the temperature of the upstairs hallway even though I am not using the AC. Another fun thing that we discovered last night is there is a setting to activate the display by tapping the device or simply by waving you hand in front of it (it has a motion detector.) We opted for the fun "waving" technique. In the middle of the night when I got up to get a drink of water I passed it in the hallway and it lit up like a nice little night light! (Brightness is also fully adjustable.)

These things are freaking amazing. I LOVE my low-tech heating system couple with this hi-tech controller!

(The third thermostat is going to grandma who can not see the numbers on hers!)

It's motion sensor also apparently detects if people are around and if they aren't nudges down the temperature a little so it figures out if people are away during the day and when they come home, and if maybe they went away for a weekend or holiday and since no one is around for a few days lowers the temps.

Yup. It also tracks and creates charts of temperature and usage for the whole year (including humidity levels)!