Ignition Transformers for Hot Water Burners

When a burner cranks, sprays fuel, and never lights, the ignition transformer is one of three suspects. We stock Allanson transformers for the Beckett and Wayne burners that run most hot water pressure washers, in 120V and 240V. Not sure which mount you have? Send a photo or call 301-519-9274 and we will match it before you order.

What a Burner Ignition Transformer Actually Does

The transformer takes line voltage, 120 or 240 volts, and steps it up to roughly 10,000 volts at the secondary. That high voltage jumps a gap between two electrodes sitting in front of the fuel nozzle, and the arc lights the atomized diesel or kerosene. On most pressure washer burners the spark runs the whole time the burner fires. If the arc weakens, the flame gets lazy, sooty, and hard to start on cold mornings before it quits entirely.

Match Three Things Before You Buy

First, supply voltage. A 240V machine needs a 240V transformer and a 120V machine needs 120V. They look identical from the outside, so read the data plate on the old unit. Second, the burner. Beckett and Wayne mount their transformers differently and the base plates do not interchange. Third, the mount style. End mount and side mount units hinge from different edges of the burner housing, and the wrong one will not sit over the electrode contacts. The burner model number off the housing tells us everything in one call.

Test Before You Replace

Half the transformers people replace still work. Kill power, then flip the transformer open on its hinge and inspect the two spring contacts underneath. With power restored and hands clear, the old counter test is an insulated screwdriver: bridge from one terminal toward the grounded base and a healthy transformer throws a fat blue arc across a 3/4 inch gap. Weak orange spark, or spark on one terminal only, means the transformer is done. Strong spark means your problem lives in the electrodes, the nozzle, or the fuel supply instead.

Allanson Transformer Lookup

Availability moves with the season. Call to confirm before a road trip.

From the Field

Most no-spark calls we take end with a 20 dollar fix, not a 190 dollar transformer. Cracked electrode porcelain, carbon bridging the gap, or corroded spring contacts between the transformer and the electrode rods will kill ignition just as dead. Pull the electrode assembly, look for hairline cracks, reset the gap to your burner spec, and clean the contact points before you spend transformer money. The other pattern is water. These rigs live outside, and a transformer that sparks fine in July starts missing in a damp November because moisture found the secondary. Keep the burner housing closed and tarp the skid. When it really is the transformer, swap the fuel nozzle at the same time. You are already in there, and a fresh nozzle is cheap insurance against the next lockout.

Related Burner and Electrical Collections

• Burner parts
• Igniters
• Burner fuel nozzles
• Fuel pumps
• Fuel filters
• Thermostats
• Switches
• Electrical components
• Hot water pressure washers

We troubleshoot burners at the counter of our Gaithersburg store most weeks. Bring the old transformer and the burner model number.

Frequently Asked Questions

What does the ignition transformer on a burner do?

It converts 120 or 240 volt line power into roughly 10,000 volts and feeds it to the electrodes. The arc across the electrode gap ignites the atomized fuel spray, and on most washer burners that spark runs continuously while the flame is on.

How can I tell if my ignition transformer is bad?

With power off, open the transformer on its hinge and check the spring contacts. A healthy unit arcs a strong blue spark about 3/4 inch from each terminal to ground in the screwdriver test. A weak, orange, or one-sided spark means replace it. This test involves high voltage, so skip it if you are not comfortable and call us instead.

My burner has spark but no flame. Now what?

Spark plus no fire points at fuel. Check the fuel level and shutoff, the fuel filter, the pump coupling, and the nozzle. A plugged or worn burner nozzle is the most common cause, and it costs a fraction of a transformer.

Are 120V and 240V transformers interchangeable?

No. The primary winding is built for one supply voltage. A 240V unit on 120V sparks weakly or not at all, and a 120V unit on 240V fails fast. Match the data plate on the old transformer or the machine wiring diagram.

Can a solid state igniter replace my iron core transformer?

Often yes. Solid state igniters weigh less and put out a hotter spark, and several are sold as direct upgrades for common Beckett and Wayne burners. Fitment is model specific, so check our igniter collection or call with your burner number.