The average life of a thermostat such as you mention is about ten years. After that period, they either fail completely or deteriorate in efficiency at a rather accelerated rate. Ergo...you'll be spending more and getting less in return because the thermostat is not accurate. It pained me as I'm not rolling in dough these days to have to replace mine throughout my abode about seven years ago. My entire energy system is electric...so there's a thermostat in each room. They're now all digital and I suspect I'll be replacing this batch within the next two to three years. Groan! If I were you, Sue, I'd replace the east system thermostat now rather than waiting for it to fail completely.

We moved into this 'new' house in July, 2005. If my thermostat begins to go, then it will be time to put the house on the market! Already had to have two faucets replaced. I might be able to do the programmable thermostat by myself. If that doesn't work, then I will call my realtor, not my HVAC people.

When am I going to develop smarts enough to NOT wear short-sleeved shirts when going to the almost-new library, that has an array of hundreds of solar panels on the roof ... or shopping malls.

I've been known to visit their information desks, teeth almost chattering, to ask whether they rent sweaters.

When I just came in, sweating!, from a hot outdoors - that's when one really freezes!

ole joyfuelled

I don't know what kind of thermostat your system has, Jim...but...I replaced a few of mine on my own without blowing up this place...and at the time I was around 69 or 70 sans a degree in electricity. LOL The digital thermostats are rather easy to install. I only needed one programmable one and I left that to my electrician. :-) As for water related equipment...faucets, toilet innards, etc...I've replaced a few of those as well over my 27 years here. However...once I had a pressure relief valve installed at the water entry pipe...my need for replacements became much, much less. The water pressure here was far too high and it kept deteriorating my facilities rather regularly until I discovered the issue.

I also installed a new thermostat myself. No problem... easy peasy. :) Plumbing isn't hard either... I took my garbage disposal out, and my dishwasher too. Again, easy peasy. In fact, I moved an outlet... and now have my microwave on a shelf, where the dishwasher was previously. Loved that idea, when I saw this in Cheryl's house.

Moni

The electro-mechanical thermostats that were in widespread use pre-digital era were simple devices that lasted forever. There was a blob of mercury in a glass vial, connected to a metal coil that would expand and contract with temp changes. The mercury would slide to one side or
the other as the temperature changed, and in doing so would complete a
circuit or switch it off. Other than the mercury in the vial, there were no moving parts and no circuit boards.

Today's digital thermostats that allow different daily schedules are much more capable but they don't last forever.

Even the old mercury thermostats were not without their need for restorative attention. They normally required recalibration about every two to three years. If you didn't have the knowledge/skills to do this...and you didn't call in an HVAC person to do it for you...your heat/cold measurement was not accurate and would call for heat/cold when it may or may not have been necessary.

The other factor that most people don't think about is that dust and air particle debris can build up behind thermostat covers and should be part of a homeowner's cleaning regime at least twice a year...more often depending on what exposure the thermostat gets. Anything that interferes with the mechanics of that piece of equipment will throw off its accuracy but most people don't recognize the deterioration until the equipment goes boots up. Their energy bill may start to rise...but it's amazing how an owner will justify that rise without giving thought to what's actually causing the rise.

Digital thermostats are less likely to have these problems but when they start to fail, there's little the owner can do to restore them for any additional, accurate life. And...as those of us who have had to change them have learned...the price of these digital wonders is about 3 - 4 times higher than the older, non-digital models. I love mine because they're very accurate and almost maintenance free...but when they go...they go...and with very little warning.

I have owned two houses (not at the same time) and have experience with the older thermostatic coil thermostats. My first had contacts exposed to the air and the second one used a small bulb of mercury. The bi-metallic elements in both lasted forever. The exposed contacts were not as reliable as the mercury switch. Once in a great while, a speck of debris would get between the contacts and prevent circuit closure. (This is a low voltage circuit, about 24 volts and powered from the bell transformer.) The mercury switch did not have such problem and has been the most reliable by far. I owned the first house 13 years and the second house 39 years have never replaced either thermostat. The only maintence I do on my present mercury swith thermostat is to pull the cover off and inspect for dust bunnies - it does collect and assortment of household dust over time. I blow these out by mouth or by a breeze from hair dryer (with heat turned off). One has to use care when blowing by mouth to avoid spittle on the parts.

I will not be so lucky if I ever get a programmable thermostat since these have electronic parts and a circuit board. These are susceptible to voltage transients and aging. Some day, I may replace the furnace with a high efficiency model and that will involve electronic controls both for the furnace and the thermostat circuit. I am not looking forward to that since we do get a number of power line lightening strikes every year. My old gas furnace has been reliable.

In all this time, I have replaced very few faucets, and merely did standard maintenance such as replace stem tip washers, repack gland nuts, and on newer faucets, replaced the "O"-ring seal on the end of the stem. Two years ago, I did replace a set of kitchen faucets because the diverter valve for the rinse hose had been ruined with some heavy handed tool work (by me). The bath tub/shower valve had to be replaced. That was broken trying to remove the cartridge after having been in place for 15 years. A had a plumber friend replace this for me since it involved cutting and soldering copper plumbing.