Resideo PA404A1025/U Pressuretrol Controller with Subtractive 1 to 5 psi Differential Pressure

The PA404A1025 is a Pressuretrol pressure controller from Resideo (Honeywell Home), 3 psi to 15 psi, subtractive differential.

On a steam boiler the pressure control is what decides when the burner stops. Steam heating works at a couple of psi; a boiler allowed to climb past that wastes fuel, bangs the mains and shortens the life of everything downstream of it. The Pressuretrol senses boiler pressure on a stainless diaphragm and breaks the burner circuit at the cut-out setting.

Subtractive differential. The cut-in is the setting, and the burner comes back on at the setting minus the differential. Set the main scale and the differential subtracts from it downward.

Getting this backwards is the classic mis-set: the same numbers on the two versions do not produce the same cycle. Check which one is on the boiler before copying settings from the old control.

This is an operating control, not a safety limit. A steam boiler still needs its own high-pressure limit and its relief valve; the Pressuretrol is what keeps it from getting there.

• Brand: Resideo (Honeywell Home)
• Manufacturer Part #: PA404A1025/U
• Type: Pressuretrol pressure controller
• Operating range: 3 psi to 15 psi
• Differential: Subtractive, 1 to 5 psi Adj.
• Sensor: Stainless Steel diaphragm
• Electrical: 0.25 A @ 0.25 to 12 Vdc; 120 Vac, Resistive: 8.3A; 240 Vac, Resistive: 8.3A; 277 Vac, Resistive 7.2A
• Maximum pressure: 20 psi
• Dimensions: 4 15/32 in high x 3 3/8 in wide x 2 1/4 in deep
• Approvals: UL Listed: File no. MP466, Guide no. MBPR, CSA Listed: File no. LR1620
• UPC: 085267064286
• Category: Steam Controls

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