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Pentair

Pentair UltraTemp Heat Pump

UltraTemp offers relay control on its three-wire remote terminals or RS-485 on a separate connector. Whichever you wire, there is a Remote Mode setting on the panel that has to agree with it, and the heat pump ignores the wiring until it does.

Two connectors, two methods

ConnectorMethodRemote Mode setting
J7Three-wire remote terminals, dry contactsRELAY
J8RS-485 serial connectionRS-485

Relay mode on J7

J7 is the three-wire remote terminal block. It works the way a pool and spa remote does: a common plus two selects, one calling for pool heating and one for spa. Drive each select from a dry contact on the module using COM and N.O so both rest open and the heat pump idles.

RS-485 on J8

J8 is the RS-485 connector. It follows the same Pentair colour convention as the pumps and the MasterTemp.

PinColourSignaliSmart Module
2GreenDATA-PORT terminal B
3YellowDATA+PORT terminal A
Pentair yellow to PORT terminal A and green to PORT terminal B, with the optional black common to G.
The same pair as every other Pentair device on the pad.

When it does not respond

SymptomWhere to look first
No response to anythingRemote Mode still set to OFF. Check this before the wiring.
Wired to J8 but silentRemote Mode set to RELAY, or green and yellow swapped.
Contacts close but nothing happensRemote Mode set to RS-485 while wired to J7.
Starts late every timeCompressor restart delay, which is normal.
Runs but never reaches setpointAmbient conditions and water flow, not the control link.

Sources