Hydrotherm 26-3005 Transformer

The Hydrotherm 26-3005 Transformer is a critical low-voltage power source designed for precision control in hydronic heating systems. Engineered for high-duty cycle performance, this 115V to 24V step-down transformer provides a stable 20VA output required to energize gas valves, ignition modules, and limit controls. In the field, this component is frequently utilized as an OEM replacement part for Hydrotherm boiler series, ensuring that the control circuit maintains a consistent 24V signal even under fluctuating line conditions. Its robust construction minimizes electromagnetic interference, which is vital for protecting sensitive HVAC control boards and 24V thermostats from premature failure caused by voltage spikes.

Technical Specifications:

• Primary Voltage: 115 VAC, 60Hz
• Secondary Voltage: 24 VAC
• Power Rating: 20 VA
• Application: Hydrotherm cast iron boilers and modular heating plants
• Component Type: Class 2 Control Transformer

Key Benefits:

• OEM Compatibility: Seamlessly integrates with Hydrotherm boiler control circuits without the need for mounting modifications or additional bracketry.
• Thermal Stability: Designed to dissipate heat efficiently, preventing core saturation and ensuring stable 24 volt AC power during long heating cycles.
• Reliable Ignition Support: Provides the necessary amperage for intermittent pilot ignition and standard gas valve actuation.
• Compact Footprint: Fits within standard electrical enclosures, simplifying the replacement process for service technicians working in tight mechanical rooms.

Common Questions:

Yes, you can increase the VA rating (capacity) as long as the primary (115V) and secondary (24V) voltages match. However, the Hydrotherm 26-3005 is specifically sized for this equipment's current draw to prevent over-fusing the control circuit.

Audible humming or excessive heat often indicates an overloaded HVAC transformer or a partial short in the secondary circuit, frequently caused by a faulty contactor coil or grounded thermostat wire.

Incorrect wiring on the high-voltage side will immediately blow the internal windings. Always verify 115V line voltage at the source before connecting the primary leads.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.