FAQs

5. How are circulator speeds selected?
The WM97+ control can select low, medium, or high speed for the
internal circulator on both DHW and Heat settings. Low speed is typical
for primary/secondary connection and may be acceptable for very a small
zone(s). If in doubt, verify the boiler out and boiler in temperature
difference is approximately 30 degrees. Higher speeds will lower the
temperature rise through the boiler.
6. What is the maximum relief valve pressure for the WM97+ boiler?
30 PSI
GAS VALVE AND CONTROL
1. What is the maximum and minimum inlet gas pressure to the boiler?
Maximum is 13” water column (W.C.), minimum is 3.5” W.C. for WM97+70
and the WM97+155, and 4.5” for WM97+110 with boiler operating at high
fire.
2. What is the manifold pressure of the gas valve?
The gas valve is a negative regulation gas valve and the manifold
pressure cannot be measured. A combustion analyzer must be used to
properly adjust the gas valve.
3. What is the procedure for converting from Natural Gas to Propane?
All WM97+ boilers are factory tested and shipped as natural gas boilers.
Every boiler comes with a propane conversion orifice and instructions.
4. What is the operating voltage of the gas valve?
This is a DC gas valve. Voltage is typically 19 to 21 volts DC measured
on the two outer pins of the gas valve connector.
5. What is the trial for ignition and number of ignition retries for the gas
control?
The ignition control trial for ignition is 4 seconds before shutting down and
recycling. The control module tries for ignition 5 times before ignition
lockout. To reset an ignition lockout, select “MANUAL RESET” on the
boiler display and follow the step and warnings. If an ignition lockout
occurs, the control module will perform a new complete ignition cycle after
a 60 minute wait.