Gas valve "ON" but won't go to "Run" mode

peterbeal

I have a HTP Elite El 301 Natural Gas boiler that when it ignites the gas valve stays in the "on" mode but will not go to the "run" mode. Then boiler will run for about 25 seconds with the display showing gas valve " on" but instead of the fan ramping up the unit slows down and the ignition stops and will not ramp up to go to " run" mode. The boiler will continue this cycle without locking out.

The gas pressures are correct. The flame rectification rod and electrode are new. The boiler is clean and nothing appears blocked. It appears to ignite correctly and goes beyond the flame rectification period but the unit won't ramp up to go in the run mode. The flame signal appears correct. Any help appreciated.

Thank you

mattmia2

What codes are set if you go in to the installer menu and look at the error code item?

peterbeal

The Boiler will continue to cycle over 3 times without giving a code or locking out. It did lockout once with a F10 error. I don't have the error code book with me but it was flame loss I believe.

mattmia2

Are you sure it is getting a continuous heat call? Try jumpering TT. It seems like if it is aborting an ignition cycle it would set a code for why.

mattmia2

Or the circulator comes on and the return water temp is above the setpoint.

peterbeal

I can try jumping it but was letting to do it's own thing. There are two boilers so this one is the follower. The code was for flame loss F 10 when it gave one. The problem could be anything which is the problem. Bad controller , circuit boards or anything.

mattmia2

Oh, if it is following the other boiler in a cascaded setup i'd look at settings and communications cable with that.

peterbeal

I will take another look at it.

Thank you