Problems with old Janitrol boiler

pgbeckwith

I have an older Janitrol boiler, probably the original one installed

when my house was built in the 1950's, that I've been having some issues

with. I turned the heat on a few weeks ago, and everything fired up as

it should. A heat wave came through, and I turned the thermostat all the

way down to turn off my heat, and the boiler and heat continued to

fire. I ended up turning off the boiler at the kill switch attached to

the boiler. When it started to cool off again, I turned the switch back

on, and nothing happened with the boiler. Tried cycling the thermostats

up and down, and still nothing.







Shortly after this happened, the snow storm that came through New

England left me without power for a few days. When it finally came back

on, the boiler fired up, but had the same issue as before with the

boiler continuing to fire, even when the temperature was well over

10-degrees higher than the temperature set on the thermostat. I started

to trace the wires back from the thermostat to see if there was anything

wrong, and when I took the gas valve cover off to see if there was

anything wrong in there, the boiler turned off. Now I'm in the same

position as I was before, with my boiler refusing to turn on. I snagged a

multimeter from work, and when bridging the "Transformer" and "Valve"

terminals on valve electronics, I only get 20v. I know at least one of

my thermostat's is working, because my second heating zone is forced

water, and that pump fires on and off as it should when I jog the

thermostat. I'm not sure what the next step would be in getting this bad

larry to turn on again.

Alan (California Radiant) Forbes

Bad Larry

You got a sticky something.



One of your electrical contacts is not breaking when reaching setpoint.



Check your:

1) Thermostat

2) Relay

3) Gas valve (I've never seen a sticking on gas valve, but you never know).

4) Aquastat relay

Mike Kusiak_2

More info

You mentioned that the circulator for the second zone goes on and off with its thermostat. What about the main zone. Does its thermostat control another circulator or is this a steam system?



Some photos of the boiler and controls would be very helpful.

John Mills_5

Gas valve

We had a Janitrol (National US) boiler in the family home, installed in the 50s. In the late 80s, the gas valve stuck open and the house started turning into a sauna. Those old pipes from the gravity days were banking like crazy I'm told. Now my Dad barely knew when end of a screwdriver to hold but he did manage to get the gas shut off to the beast. Gas valve was replaced but the damage was done. Year or so later she split open. 

Tim McElwain

Please identify

the gas valve Make and Model number if you can. Some pictures of this would help so I can identify the problem. Some of those old valves had a manual switch on them and they are known to get tripped into manual by accident. They actually should be removed and replaced by a modern dual seated gas valve. If the unit  will not shut off next time then remove the wires from the gas valve, if it still will not shut off the gas valve is defective and is allowing gas to flow with no power on.

RobertClem

worcester, mass

I have a Janitrol gas boiler with 405,000 btu imput. I have no idea of the age. The plate on the boiler says "Manufactured for Surface Combustion Corp., Toledo, Ohio by National Radiator Corp, Johnstown, PA.



My problem is that two or three times a heating season, the heat will just shut down with the pilot remaining on. I have to push the reset button, hold for a few seconds and she kicks back on. My concern is I want to address the problem so that it will not go off should I be traveling or away for an extended period. There are no markings on the reset valve.



The other control is an automatic control magnetic valve (V166Aic6, pressure 4 oz, 20 watt, 4 volt) which was manufactured by Minneapolis Honeywell Regulator. Do you think this control might be my problem? It has an automatic/manual adjustment and it is set to automatic.



Finally, the only electrical switch to the boiler is behind it. When we shut it off to look at thte automatic control, the boiler continued to run, so the only electrical control to shut off the gas seems to be at the thermostat in the house.



What say you?

Tim McElwain

The valve is an old

Series 10 Honeywell valve which has really done its duty.



I need to see pictures of some of the other controls so I can identify them and give you some direction to go. I for example do not know if the pilot at some times was converted over or what the reset actually does in your sequence of operation.



There should however be one switch that shuts of all power to the system so that is off some concern.



I am glad to try and help you but some pictures would help.