Home Retrofit

Auxiliary heat lockout settings critical to energy savings on HP installs


Through work quality verifications, Energy Trust has identified a concerning trend of improperly set auxiliary heat lockouts on heat pump and heat pump advanced controls installations.

Energy Trust’s Specifications Manual requires auxiliary heat to be locked out when outdoor temperature exceeds 35°F and encourages auxiliary heat lockout to be set lower when the system allows. Locking out the auxiliary heat on a heat pump’s controls is the primary way a heat pump saves energy and ensures that the heat pump is used as the home’s main heat source. Not following auxiliary heat lockout specifications can impact a contractor’s trade ally star rating and can even lead to disciplinary action.

If you have questions, please reach out to the Residential trade ally team at 1.866.365.3536.