Old thermostat Honeywell T451A1124 in series with circulator

Thinkgene

I`m having my old New Yorker oil furnace taken out and a gas boiler for baseboard heat installed. I have T451A thermostats (really old!) in two zone heating. I intend to keep them. My installer wants to use 24v. I don`t see why unless these thermostats will not control the baseboard circulators. I live on Long Island,and these thermostats are still used widely. I am satisfied with their operation and see no reason to replace. Not broke. Why replace? Comments?

                                   Gene 

Robert O'Brien

Digital

is superior, but you can certainly use the existing thermostats if you prefer

Big Ed_4

T451

Long Island used line voltage thermostats for hydronic heat from 1960 - the mid 1980s . I assume you have the model with lever on the top since your are satisfied with them ..



The new gas boiler will run on low voltage though . You can use the line voltage thermostats if you want . For efficancy sake you would want to have a demand control on the gas burner ... Either use relays , install an outdoor reset control .or better yet both.. They help out saving on system loss ...

Robert O'Brien

Longer than that!

Started in the 50's and went until most new homes had CAC,early 90's. My favorite is very common use of 3 wire,necessitating the use of a RIB relay on a retrofit!

Robert O'Brien

Longer than that!

Started in the 50's and went until most new homes had CAC,early 90's. My favorite is very common use of 3 wire,necessitating the use of a RIB relay on a retrofit!

Big Ed_4

3 Wire

You mean when they picked up the thermostat at the safety switch ...