Harold Kestenholz
Depending upon the watts drawn for the control board of the heater, there might or might not be enough wattage to power the board and three zone valves. Three zone valves of 6W is 24W out of a 30VA or wattage transformer. If the control board always uses less than 6VA, then the setup might be OK. Overdrawing would make the ignition drop out and perhaps damage the board and/or transformer. A sure way to avoid the problem is to pay the price of a new separate 40VA transformer for the zone valves.
