Hayward H-Series Heaters
Hayward has been producing different models of gas heaters under the H-Series label. It can be confusing when you have a problem and find information talking about a Hayward heater but not your specific model.
Universal H-Series
The Universal H-Series consist of the HXXXFDN, HXXXFDP, W3HXXXFDN, and W3XXXFDP models. N denotes Natural Gas, and P denotes propane gas. FD means the heater is Forced Draft using a blower to create air flow.
Cupro nickel is the standard heat exchanger on the Universal H-Series gas heaters. Cupro nickel heat exchangers last longer than standard copper and superior corrosion resistance protects the heat exchanger from damage and premature failure caused by unbalanced water chemistry.
The INSTALLATION, OPERATION, & SERVICE MANUAL for the HXXXFD Series is here.
Universal H-Series Diagnostics Guide provides detailed diagnostics for troubleshooting problems and error codes.
HXXXIDL Models
XXX is the BTU rating of the heater in thousands and IDL means "Induced Draft Low NOx".
The IDL models use an air blower for the induced draft.
HXXX Models
The INSTALLATION, OPERATION, & SERVICE MANUAL for the HXXX Series is here.
The HXXX comes in a millivolt model and an electronic ignition model.
The millivolt heater must be lit manually. The millivolt operated heater is equipped with a standing pilot and a thermopile (pilot generator). All of the electric current required to operate the controls within the heater is provided by the pilot generator. No external wiring or electrical connections are required.
The electronic ignition models are lit automatically on each call for heat. The electronic ignition system is equipped with the same basic controls as the millivolt operated heater but a direct spark ignition device (DS) is used to automatically light the main burners on each call for heat. With the DS module these controls operate on 24 volts so an external power source is required.
The HXXX models use an natural draft and do not have an air blower.
