Install Instructions

AQUA PLUS indirect-fired water heaters — Product Manual

Troubleshooting

(continued)

Boiler relief valve lifting or weeping

1 Undersized expansion tank?

• Insufﬁcient allowance for expansion on the boiler side can cause the boiler pressure relief valve to lift.

• The additional quantity of boiler water contained in the outer tank must be considered when sizing the

boiler side expansion tank.

AQUA PLUS

model

Boiler side

volume —

gallons

35 1.6

45 1.9

55 2.2

85 2.5

105 3.5

2 Faulty boiler expansion tank?

• Is the expansion tank defective, waterlogged or improperly charged?

• Check for failed gaskets or bladders, or a faulty Schraeder valve.

• Use a tire gauge to check the charge pressure of the tank.

• Turn the boiler limit up to a higher setting and let the system run at a higher temperature. This will

simulate maximum expansion in the boiler system.

• If the boiler relief valve lifts and/or there is a signiﬁcant increase in the boiler system pressure, the

expansion tank is ﬂooded or undersized.

3 Faulty boiler relief valve?

• Is the boiler pressure relief valve functioning properly? Dirt and water deposits can accumulate under

the valve seat.

4 Faulty boiler ﬁll valve?

• Is the valve ﬁlling to the correct pressure?

Part number GL-E223-ADOC 0311