How to use this worksheet
Walk to your current water heater with a flashlight, a tape measure and this page. Most answers take a look and a note, not tools. Where a question asks about the gas line, read what is printed or stamped on the pipe or fittings if you can, but do not loosen, move or test anything on the gas system yourself.
Bring the completed worksheet to each plumber's site visit. When every plumber starts from the same facts, their quotes are much easier to compare, and you will notice quickly if one of them skipped a step.
Section 1: The current heater
- Type: gas tank, electric tank, or existing tankless
- Location: garage, interior closet, exterior wall or attic
- Brand, model and approximate age from the label
- Vent: metal flue through the roof, side-wall vent, or none
- Seismic straps present on a tank
- Does a furnace or other appliance share the same flue?
Section 2: Utilities near the heater
- Gas shutoff valve at the heater, and the visible pipe size if marked
- Distance from the gas meter to the heater, measured along the wall
- Other gas appliances: furnace, range, dryer, pool heater, fireplace
- Nearest electrical outlet and whether it is a GFCI outlet
- Nearest floor drain, laundry drain or other place a condensate line could go
- Water lines at the heater: copper, galvanized, or flexible connectors
Section 3: Peak hot water demand
| Fixture or appliance | Runs at peak? (yes or no) | Notes |
|---|---|---|
| Shower 1 | ||
| Shower 2 | ||
| Bathtub | ||
| Kitchen sink | ||
| Dishwasher | ||
| Clothes washer | ||
| Other |
Reading your answers
- IfSeveral gas appliances and a long run from the meterThenExpect the plumber to look closely at gas line size; a new run may be part of the quote.
- IfThe flue is shared with a furnaceThenAsk how the furnace will vent correctly once the tank is removed.
- IfNo outlet near the heaterThenPlan for an electrical outlet; most gas tankless units need power.
- IfGalvanized water lines at the heaterThenAsk whether the connections should be replaced to protect the new unit's inlet filter.
Common questions
Do I need to know my exact gas pipe size?
No. Note what you can see; the plumber will confirm size and length. Never disassemble gas fittings to check.
Why does the furnace flue matter?
If the old tank and furnace share a flue, removing the tank changes how the furnace vents, which has to be checked.
Should I share this worksheet with every plumber?
Yes. Giving each the same information makes quotes easier to compare.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.