ICP Metering Device .042 Chatleff Piston, 1173634
The ICP 1173634 is a genuine International Comfort Products .042 Chatleff metering piston, the smallest bore in our ICP piston lineup. ICP builds equipment for a whole family of brands: Heil, Tempstar, Comfortmaker, Arcoaire, Day & Night, KeepRite, AirQuest, EcoTemp, and GrandAire. Those brands share ICP part numbers, so 1173634 is the OEM replacement wherever an ICP-built unit's parts list calls for a .042 piston. HVAC service techs and DIY homeowners use it to restore proper refrigerant metering after a coil swap, a clogged or damaged piston, or a system repair.
Is the .042 Piston the Right Size?
A metering piston is a precision orifice. Its bore controls how much liquid refrigerant flows into the coil. The equipment manufacturer sets the size for each specific unit, coil, and refrigerant, so you can't reliably choose a piston from tonnage alone. Budget Heating lists the .042 as a general reference for about 1.5-ton systems. However, ICP's own parts list for the PHN442 and PHN448 R-410A package heat pumps calls for two .042 pistons per unit. The same bore can serve very different equipment.
The surest match is the size stamped on the piston you're replacing, or the piston size shown in your unit's parts list, installation instructions, or charging chart. Installing the wrong size can starve or flood the coil and affect capacity, superheat, and compressor protection.
Ideal for: Replacing a .042 piston in ICP-built Heil, Tempstar, Comfortmaker, Arcoaire, Day & Night, KeepRite, AirQuest, EcoTemp, or GrandAire equipment when the parts list or the old piston confirms the .042 size.
Need a larger bore? Step up to the ICP .046 Metering Piston, 1173650 when your equipment calls for the next size.
ICP is part of Carrier, but Carrier-family brands generally use their own piston part numbers. Check your unit's parts list before using an ICP piston in non-ICP equipment.
Is the .042 piston only for 1.5-ton systems?
No. Piston size is set per model. For example, ICP's PHN442 and PHN448 package heat pumps use two .042 pistons each. Always match the size your equipment specifies.
Where is the piston size marked?
The size is typically stamped on the piston itself and listed in the unit's parts list or charging chart. Compare both before ordering.
What does "Chatleff" mean in the part description?
ICP's parts lists describe 1173634 as a "Piston Chatleff .042," which identifies the style of piston and the metering fitting it's used in.
What happens if I install the wrong piston size?
A bore that's too small can starve the coil, and one that's too large can overfeed it. Either can hurt capacity, efficiency, and compressor protection, so verify the size first.
