Vertex GPHE50 100 Knocking Sound
by Frank Wild
Our gas-fired Vertex water heater has developed a knocking sound every time it fires up. The unit is about 3 years old. The sound is coming from within the hot water tank, not from any exterior connection. The knock sounds like pipe reacting to thermal expansion. Since it is part of the plumbing of the house, the sound travels through the pipes. What is the cause and possible solution?