House in Progress Diary

Installling a Thermostat

Last night we upgraded our thermostat. It was really easy--here's how it went.

The Problem
Our old version was probably twenty years old and didn't have any of the modern timer features designed to reduce energy costs. With cooler nights starting already, we were nervous about high heating costs.

Our Solution
Most modern thermostats claim they can reduce your heating expenses by up to 35%, when used in accordance with their gudelines.

Read on for how it went...

Why we chose what we chose...

Today's models provide a range of options and flexibility based on your needs and what you want to spend. There are systems allowing for different settings for weekdays and weekends (often called '5-2' systems) available for under $40. Others allow differences between weekdays, Saturdays and Sundays ('5-1-1' models) for under $50. Finally, some models allow a different setting every day of the week (7-day models) for $50 to $100. Higher end options include large, backlit screens or even the ability to monitor and change your heating over the Internet. Those options can push costs from $100 to $300. We chose a fairly simple 5-1-1 model to give us some flexibility at a reasonable cost.

This will allow us to program the heat to come on before we rise in the morning and to be off during the day...then it comes on before we come home again. Toasty. Conserves energy. Weekends are different start and stop times...so they can be programmed separately. Of course, you can override everything manually if you need to, as well.

How it Went
Our previous thermostat had a single control for the desired temperature along with an on/off switch.

To replace it, we followed four easy steps:

1. Remove the previous thermostat.
- The faceplace should snap off easily in most cases.
- You'll need a screwdriver to remove the base and/or mounting bracket.

2. Disconnect the wiring from the old unit and label the wiring.
- The wiring you will have will vary by situation.
- You'll find each wire labled on the contact point on the base of the former thermostat. Here are some of the common wire labels:
- RH - Heating Transformer
- RC - Cooling Transformer (in case you have AC...we don't)
- W - Heating Control (this is most critical)
- C - AC power to run the thermostat (uncommon on old houses)

3. Affix the wiring to a pencil or large object.
- This prevents the wiring from falling back in to the wall.
- In our case we used a pen and string.

3. Attach wiring to new thermostat.
- Your instruction manual should provide more specific details here.

4. Affix the faceplate to the wall.
- This should be pretty straight froward.
- You may need a more powerful drill to make new holes. We used a cordless.

Tools & Material We Used
- Thermostat
- Screwdriver
- Cordless Drill (optional)

Other Useful Resources
For more detailed instructions, you can try The Complete Guide to Home Wiring from the Black & Decker Home Improvement Library. (Instructions for replacing a thermostat are on p. 106.)

Posted by aaron on October 23, 2003 at 11:32 PM (2)