Taco Room thermostat

Old 07-21-06, 05:49 AM
Thread Starter
Join Date: Mar 2002
Location: illinois
Posts: 184
Received 0 Votes on 0 Posts
Taco Room thermostat

I would like to use a Taco 568-14 thermostat to replace my exisiting Honeywell T87 thermostat. I have a hot water gas boiler but no Taco zone valves. Instead, I have Honeywell relays that control the booster pumps.

The Taco 568-14 room thermostat is designed for control of Taco Zone valves. It is a simple thermostat with a positive snap action switch and a spiral type bi-metal element for sensitive control. It doesnt have a mercury switch like the Honywell does.

Can I use this Taco thermostat in place of the honeywell T87? Thanks!!
Old 07-21-06, 02:16 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
Probably. I am not familiar with the Taco thermostat but often a thermostat for a zone valve will have a SPDT switching action. There will be three wire terminals, one of which is a common. The common terminal will "make" (connect) to one of the two remaining terminals on a "call for heat" and drive the zone valve open. When the thermostat has been satisfied the common terminal will "break" (disconnect) from this first connection and make to the other connection and that will drive the zone valve closed.

What you will need to do is determine which terminal is common and which terminal the common closes to when calling for heat. Ignore the third terminal. It will not matter which of the two wires from your thermostat cable is connected to the two identified terminals on the Taco thermostat.
Old 07-21-06, 02:51 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 14,401
Received 37 Votes on 35 Posts
Snap action thermostat

That stat is about the cheapest thing you can possibly buy. They are notoriously inaccurate, even worse than T87's. I suggest an inexpensive White Rogers or Honeywell digital. They don't have to be complex or programable. Honeywell makes a digital round thermostat which is a direct replacement for the T87 you have now.
Every single one I've installed customers have really liked.
Old 07-21-06, 03:59 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
...even worse than T87's
HEY! The T87 is the best $2.00 thermostat on the market. Too bad you can't buy one for $2.00

I agree with Grady about purchasing and installing a digital thermostat. Even a $10.00 ($20.?) LUX brand digital would be an improvement over an old bimetal thermostat.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: