New thermostat for hot water boiler...don't need a smart one

FloMo201

Hi All,

As we near heating season in the northeast, I remembered that 1 of 4 thermostats died at the end of last winter. I have yet to replace it. I only have 2 wires to the thermostat, and a 24v transformer at the boiler, no C wire. 4 zone vales, and 1 circulator. Boiler is a Peerless MI. I'd like to change all 4 thermostats and need a recommendation.

Google gave me the Honeywell T4 and the Honeywell Home XP2…both simply and not smart thermostats from what I can tell. I also understand that Honeywell has RedLink, which I think solves my no "C" wire but communicating wirelessly.

Any recommendations would be great. Im just trying to keep things simply…seems like we have enough complication in our lives.

Thank you, Flo

FloMo201

I should have noted that I have service set up for the boiler already and spoke to them about this. They came back with Honeywell T6, which appears to be a smart thermostat and needs a "C" wire to operate…so I thought I'd post here before they do anything.

Flo

Alan (California Radiant) Forbes

These are the thermostats that I stock on my truck. Neither of them need a “C” wire.

White-Rogers 1F80-361
Honeywell PRO 6000, model TH6110D1021

Last time I checked, the W/R is a bit less expensive. Also, the W/R has the wire opening on the right hand side of the baseplate and the Honeywell has it in the middle which can make a difference when trying to cover up holes in the wall.

EdTheHeaterMan

The simplest thermostat is one that has no electronics, no batteries and no programing available. WR 1C20-101. it is a snap action set of contacts that are triggered by a bi-metal spring that bends with the temperature.

you only get 1 temperture choice that is alwayse the same 24-7.

If you want programing with only 2 wires then you will need something like 1F80-361 that requires replacement batteries. that means a no heat call in about 2 years the will remind you to change the batteries in the other 3 thermostats. These programable thermostats will have more features than you need like Cooling and Fan operation and eved reversing valve operation for heat pump applications. The Analogue snap action thermostat is the lowest cost and easiest to understand thermostat.

One Big Caution

If you are using a Taco 570 (three terminal) zone valve, you MUST set the heat anticipator to the shortest setting on those thermostats. otherwize you may burn out the heat anticipator resistor, rendering the thermostat in the failed open position. (or always satisfied position)

pecmsg

you could pull a new 5 or 8 wire

EBEBRATT-Ed

How difficult is it to rewire the stats? That would be my first choice if it can be done reasonably. It eliminates batteries and communication issues.

HVACNUT

The T6 Pro non WiFi takes 2 AA batteries. It does also have a C terminal if wanted. The T4 is really all you need. I like them better than the WR 1F thermostats. Small display screen on the WR. In the T4 Installer Setup (ISU), you can eliminate any programmed scheduling so it'll be just a regular ole 2 wire heat thermostat No "Hold" button needed. Its very easy to do.

Jamie Hall

T87 for the win!

FloMo201

Thank you all. I will discuss further with the outfit servicing the system. I am going to have them install them.

As for re-wiring….first floor looks like a no brainer with an unfinished basement. Access to the second floor (2 zones there), well not sure I'd know how to get it done, but Im guessing they would and have tackled this before

Thanks again, Flo

HydronicMike

Aren’t the Honeywell “T” stats being discontinued T4, T6, etc?

Alan (California Radiant) Forbes

https://forum.heatinghelp.com/discussion/comment/1903978#Comment_1903978

If you go with a non-WiFi thermostat, the existing two wires are adequate.

pecmsg

hit the yard sales and find an old T-87

Steamhead

White-Rodgers makes a simple, heat-only, non-electronic, mechanical thermostat that does not need batteries:

https://www.supplyhouse.com/White-Rodgers-1C20-101-Single-Stage-Snap-Action-Low-voltage-room-thermostat-with-wall-mount?utm_adgroupid=176777930117&utm_targetid=pla-2465212685004&utm_product_id=1C20-101&utm_matchtype=&utm_adtype=pla&utm_category=HVAC&gad_source=1&gad_campaignid=22357738074

It even comes with a wall plate to cover holes from a previous thermostat. This was our go-to in rental properties since it eliminated maintaining batteries.