This Pump Head has an internal relief valve. It comes standard on furnaces starting in 2011. This pump head will replace the 32327, You can hook it up the same way that you hooked up the 32327 Pump Head. Or you may use the new method of installing per the Clean Burn service bulletin. The check vavle and relief valve or the relief valve assembly will no longer be available through Clean Burn or Clean Burn distributors.