Refrigerant Pressure Switch Chart (High, low, Fan Cycling) Peanut Type
Mar 24, 2025
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Below is a table of "peanut" pressure switches. The rows are the type of pressure switch and the columns are the refrigerant it applies to.
The resulting number is the Johnstone part number that can be given to a counter guy or use in the app.
1. Verify the Refrigerant type you are using
2. Verify which function (High Pressure, Fan Cycling, Low Pressure)
3. Get your part number
Ex. " I need a fan cycling switch for an R410a unit."
You then would read the the table and the correct selection would be a B18-784
| TYPE | R410A | R22 | R404A |
| High Pressure | B18-810 | B18-799 | B18-804 |
| Fan Cycling | B18-784 | B18-780 | B18-782 |
| Low Pressure | B18-825 | B18-817 | B18-814 |
These are merely best suggestion. If we do not stock the one you need, give us a call and we can find a suitable replacement.
