RUUD 90 plus and heat pump connection - http://www.hvacmechanic.com/ Forums

Original message

siberohvac

66.129.154.134

"RUUD 90 plus and heat pump connection" , posted Sat 5 Jul 13:43

Last year a contractor replaced my old oil furnace with a new RUUD Achiever gas furnace but never connected the outside heat pump to the system ! I did not use the heat pump for heating at the time (too cold) and the t-stat was set to Emergency heating. Now I want the air conditioning of the heat pump but the wires aren't connected. How should I connect the wires to the furnace control or t-stat or do I need to get some kind of a relay as I was told ? There is a 5 wire cable coming in from the heat pump. There is a diagram to connect an ac unit on the RUUD control board but not for a heat pump (heating and conditioning)Can anyone help ?

Naturally If i'm asking it is because I can't find the contractor who replaced the old furnace with the RUUD; he just disapeared.

Trying my best

Replies:

Houston204

98.196.66.53

"Re(1):RUUD 90 plus and heat pump connection" , posted Sat 5 Jul 15:25

The problem with dual fuel systems is that your heatpump can lock out on high head pressure if you run gas heat and heatpump at the same time.

A fossil fuel kit will overcome this problem with a duct temperature sensor to indicate when to lock out the outdoor unit and only run gas heat.

A Honeywell Visionpro TH8320 stat with an outdoor temperature sensor will also support dual fuel systems.

The paragragh above the red box is for fossil fuel.

If you have a Ruud or Rheem outdoor unit sub B for O and configure your multistage heatpump stat to energize the reversing valve for heating instead of cooling (as with the O application).

COLOR CODES WILL VARY. Varify your color codes by removing the panel a checking yours. Remember to remove power to the furnace before working on this.

"Tip of the Day" Remember to remove power first.