Thermostat problem?

I have an OLD steam boiler (Pennsylvania Furnance & Iron Co, Boiler # 3023 SA, Serial # 9-38062-16). It had been working fine until the other day when there was no heat. I checked the pilot and it was lit so I disconnected the thermostat. I have two wires (R & W). When I connect them together the boiler kicks on with no problem. But when I connected the wires to a new thermostat (Honeywell CT87K), the blower would not come on even with the temp cranked all the way up. The temp is now stuck at 62 even with the T-stat set to 70. I even bought another CT87K and tried that and had the same problem.

Any ideas?

 

Do you know the voltage on those two wires? That thermostat is only good for 24 volt applications.

 

What did you mean that the blower wont come on? You said that it has a pilot, so it's a gas boiler correct?
Is it a conversion type burner, with a draft inducer fan?
If so, I'll assume that it has a 24 volt control circuit. The CT87K is the regular, round heat-only stat. Did you install the new sub-base as well?

 

Thanks Grady. That's my problem. It's a 750 mv application so I have the wrong thermostat.