First floor zone

jogrady

@delta Hot water slant fin boiler baseboard I have three zones . Two work well and the first floor zone is where the problem Is
When my first floor calls for heat the boiler comes on and then shuts off quickly on and off. The other two zones the boiler comes on and runs ok -

newagedawn

check t stat,

Lance

Some zone valves use heaters to open them require a setting on a thermostat heat anticipator to be set at 1-1.2 amps. It can be measured. Any thing less and this will preheat the stat too quickly. Kept this way for too long, about a year, and it will burn out the zone valve heat coil. The diagnostic questions are what are the controls doing and what is causing it. If it is not a control problem and the stat is normal than it might be responding to heat. If it is above the heat source, move the stat. As there are three zones, wiring conflicts can occur when during different sequences a problem exists. Must test in all conditions. My first check for this zone would be it's wiring and its actions. Don't discount wire size, proper connections. Bell wire, 22 or smaller is too small for thermostat wire. 18 gauge is my minimum.
Good luck.

Paul48

Put the zone valve in manual bypass.....if the problem goes away.......bingo!