We got a tankless water heater installed a few weeks ago. It is a 199,000 BTU model (don't know brand). Our gas line is 1.25" to the house and the plumber ran 1" to the water heater and .75" to the gas stove. 199K BTU is in excess of what is needed to run all of our hot water using items at the same time.
When you turn on the hot water from a fast-flowing faucet (e.g., our shower) the pressure drops sharply. The plumber has been back with a representitive from the water heater company. They used a manometer (sp?) to measure the pressure. When no water is turned on, our pressure measures 10 (not sure of the unit--guessing psi) and then when you turn on the shower, the gas pressure drops to 2 which greatly reduces the water pressure. The plumber and tankless rep said it must be the gas regulator. We had the gas company come out and replace our regulator. No change.
Anyone have any ideas on what could be causing this??
Thanks in advance.