Zone Problems with Boiler

[heatwanted]

I have an older gas boiler HW heating system with a taco circulator pump for each zone that worked fine last season. When turning it on for the 1st time this season I found a problem with the boiler not running on one of the zones.

If I turn on the heat to zone 1 I hear the system actuate(clicks and such)and the boiler fires up and runs for about a minute and then shuts down.

If I turn on the heat to zone 2 the system actuates and the boiler fires up and runs fine.

While zone 2 is running if I turn up the thermostat for zone 1 the circulator pump turns on and runs fine for zone 1. But, when I turn down the thermostat for zone 2 the boiler shuts down even though zone 1 is still calling for heat.

I attempted to figure a solution searching online and since it had an old/original S8610U Intermittent Pilot Control Module I swapped that out yesterday with no improvement.

Thank you for any suggestions!

 

[ShaunCorbs]

Sounds like a controls / relay issue and not a boiler issue

 

[heatwanted]

UPDATE!

Problem solved(fingers crossed)after looking at the most obvious thing that I should have realized to do in the 1st place.

When I turned the thermostat up to call for heat in zone 1(1st floor) the boiler responded, ignited and ran for around a full minute each time. This made me just skip the step of checking the thermostat itself since a signal was obviously getting to the boiler.
The existing thermostat is a dumb, heat only Honeywell ct87k that is 5 years old. Since the unit was responding to the thermostat I figured it was a long shot but I jumped the wires at the thermostat and the system not only responded and fired up, but it kept running normally. I just finished installing a new Honeywell ck87k that I grabbed at Lowe’s and the system is running fine.

Being such a rudimentary heat only thermostat I figured if the system responded and ran for at least a minute the comms from the Thermostat were fine.

 

[ShaunCorbs]

Unless it had a delay timer built into the unit to stop firing every 5 minutes etc ?

 

[John.g]

UPDATE!

Problem solved(fingers crossed)after looking at the most obvious thing that I should have realized to do in the 1st place.

When I turned the thermostat up to call for heat in zone 1(1st floor) the boiler responded, ignited and ran for around a full minute each time. This made me just skip the step of checking the thermostat itself since a signal was obviously getting to the boiler.
The existing thermostat is a dumb, heat only Honeywell ct87k that is 5 years old. Since the unit was responding to the thermostat I figured it was a long shot but I jumped the wires at the thermostat and the system not only responded and fired up, but it kept running normally. I just finished installing a new Honeywell ck87k that I grabbed at Lowe’s and the system is running fine.

Being such a rudimentary heat only thermostat I figured if the system responded and ran for at least a minute the comms from the Thermostat were fine.

"While zone 2 is running if I turn up the thermostat for zone 1 the circulator pump turns on and runs fine for zone 1. But, when I turn down the thermostat for zone 2 the boiler shuts down even though zone 1 is still calling for heat."

Glad you solved it by renewing Zone1 stat, when you turned down Zone2, above, and the boiler shut down, did Zone1 circ pump continue to run or did that too stop?