During the summer of 2008 I installted a tankless water heater (Bosch Aquastar 1600H-NG) in my 102 year hold home. After some modifications to the water and gas lines it seemed to work rather well though it never delivered the savings on natural gas that it claimed.
When the weather here in PA began to get colder I noticed that my hotwater took longer to heat up and evenutally I had to turn the power on the unit to maximum (90* rise). However, for the past week or so I've had almost zero hot water output. I've traced the problem back to gas flow. When my gas furnace fires up I see a noticeable drop in the gas pressure to the water unit and if it is running the flames die down. All of the gas lines to the unit are run with 3/4" black iron as per the manufacturer's specifications, as are the rest of the gas lines in my home. I believe the problem stems from my gas meter restricting flow.
Currently, my main service comes in through 1 1/2" galvanized which is then shrunk down to 1/2" to the meter. The meter then expands to 3/4" for my lines. The meter itself has no restrictions and is connected to the downsized 1/2" pipe via a coupler which is 1".
My questions are as follows:
1) Can I simply convert the lines to the gas meter back to 3/4" (or 1" perferably)?
2) Has anyone else in the 19095 zip code (or surrounding area) installed a tankless unit and run into a gas flow problem?
3) Do these types of units really offering a savings over a tank? I like the idea of not storing excess water and would really like to make this unit work.
Any insight out there would be a huge help. Thanks!