Propane space heater fan / gas solenoid problem

Hello, I'm hoping you can help me,

I've recently bought an old propane workshop heater which has a voltage selector switch to choose between 110v and 230v. On the inside is a dual voltage AC fan motor which has given up on me. I replaced the motor with a 230v only model and then realised the gas solenoid valve has a single rating of 110v and is no longer functioning after reducing from 4 wires on the original motor down to 2 on the new one. Can someone explain how the solenoid might have been able to work in this scenario as there's no visible step down transformer? Obviously I'm missing two wires but it's the 110v solenoid that's confusing me. Could the original motor have somehow stepped the voltage down and then supplied it to the solenoid? Surely running it at 230v would just destroy it.

John

Are you in the United States? If so, then consider that US 220V is known by a variety of names, such as split 220V, that describe how it is wired. In other words, there is a neutral line ("grounded conductor", not ground conductor). The voltage is 110V from each live line (often two black or red + black) to this neutral (white) line. It is quite common to have appliances that run on 220V, such as a cloths dryer or electric stove, that have 110 V accessories, such as light bulbs. The light bulbs are powered by one live line plus the neutral line. In fact, the power to your house will have both sides of the 220V line and the common. That is why you can have both 220V and 110V circuit breakers in the same box.

Such 220V "split" appliances usually have 4 wires, two for the power (colored, but neither is white nor green), a white for the grounded conductor, and green for the ground. Older installations may only have three wires and no green.

The codes are quite strict on how these appliances are wired. If in doubt, get an electrician or the NEC code summary at a home center.

John

Thanks for the reply. I'm in the UK where the voltage is 230v. 110v is used by site workers who use step down transformers.

It is possible the original motor with 4 wires had a tap on the field to give the 110V, like an autotransformer. I am not that familiar with UK wiring, but I suspect you will need a small transformer to operate the valve. Such valves in the US are typically 110V, 24V, or 12V AC. 24V AC is very common for controls. My own home is almost all 24V AC for heating controls, and that voltage is derived from a transformer. I suspect 24V transformers for controls are also quite common in the UK.

John