M55 Thermostat or controls

I have a M55 Cast Insert. Recently, on High-Low operation, the stove will run on high, get to temperature on thermostat, switch to low. Then for some reason, when the temp drops and the thermostat calls for more heat, the stove won't go back to High, stays on Low. Any ideas? Thanks

Batteries weak maybe.

That would be my guess 2.

What stat are you using?

No batteries, just the basic Luxpro PSM30SA that came with the stove.

What do you have the anticapator set at?

Try turning the stat temp down and then back up. Could be stick contacts.

Not sure, what should it be set to? Contacts are okay.

Depends on how much temp variance you want. Not much of a manual. But here is what I found.

This might help.

Found this one also, going to set at .6 and see if that helps.

It says to set to 1.2 for millivolt. The M55 should work with millivolt stats. That is what I have on mine! If the .6 doesn't do it try the 1.2 setting.