Raypak 006719F Unitherm Governor for Polymer Headers, 206A-406A, 207A-407A, RP2100 R185A/B-R405A/B Pool Heaters

The Unitherm Governor is the thermostatic mixing valve in the inlet/outlet header. It holds the water inside the heat exchanger between about 105 and 115 degrees F, warm enough to keep condensation off the burners and cool enough to slow scale in the tubes. This is the version for polymer (Capron) headers.

• 206A, 266A, 336A and 406A heaters with polymer headers, built from October 2004
• Low NOx 207A, 267A, 337A and 407A heaters with polymer headers
• RP2100 R185A, R265A, R335A and R405A with polymer (Capron) headers, built November 1998 to early 2004
• RP2100 R185B, R265B, R335B and R405B with polymer headers, built October 2003 to October 2004

Not for ASME metal headers: older metal headers use governor 062234B, and on bronze headers the governor comes only as a complete governor and bypass assembly.

• Raypak part name: Unitherm Governor (U.G.)
• Snaps into the U.G. retainer plug, Raypak 006720F, next to the outlet connection on polymer headers
• The plug gasket is a separate part, Raypak 800365

Raypak's test: place the governor in hot water above 110 degrees F and watch for it to move against its spring. No movement means it should be replaced. Do not heat it with an open flame.

To change it, the manual has you shut off water, gas and power, relieve pressure, drain the heat exchanger, pull the retainer plug, snap the new governor onto the plug and refit it with a non-petroleum grease on the gasket.

Raypak recommends a new governor whenever a tube bundle is replaced, because the conditions that ruined the bundle have usually damaged the governor and bypass as well.