Replacing a Vent-Limited Gas Water Heater in a Condo Closet
A condominium owner wants to replace a 12-year-old 40-gallon atmospheric gas water heater with a 50-gallon power-vent model. The existing heater sits in a 30-inch by 36-inch closet with an 8-foot ceiling and a louvered bi-fold door opening to a 10-foot-wide hallway. The 4-inch galvanized vent connector rises 3 feet into a 6-inch lined masonry chimney. The T&P relief valve has a 3/4-inch outlet, but the discharge is reduced to 1/2-inch copper and ends 18 inches above the closet floor; there is no drain pan. The building has a 1-inch water service, a reduced-pressure-principle backflow preventer at the meter, and a pressure-reducing valve set at 55 psi. There is no thermal expansion tank. The owner's handyman proposes to reuse the existing vent and discharge piping and to skip a permit because "it is a like-for-like swap." The local authority has adopted the IPC with Connecticut amendments.
1. Identify the relief-valve and thermal-expansion deficiencies in the existing installation and state the corrections required before the new heater is placed in service.
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The 3/4-inch T&P outlet cannot be reduced to 1/2-inch copper. Relief-valve discharge must be full size, use approved material, flow by gravity, have no traps, and terminate not more than 6 inches above the floor or a receptor with an air gap. The present 18-inch termination and reduction are both defects. Because the building has an RPBP and a PRV, the water heater is on a closed system; thermal expansion has nowhere to go. The dripping T&P valve and the 145 psi gauge reading are consistent with expansion, not necessarily a bad valve. Install a listed expansion tank on the cold-water line between the backflow preventer/PRV and the heater, sized for the system volume and temperature rise, and set its precharge to the supply pressure. Add a drain pan with a 3/4-inch indirect drain where leakage can damage the closet or adjacent units. Do not remove or plug the T&P valve; test it and replace it if it fails to reseat. The discharge must remain full size and gravity-drained.
2. Evaluate whether the existing closet and chimney can support a 50-gallon power-vent heater, and list what must be verified or changed.
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A power-vent heater does not use the existing 4-inch galvanized connector and masonry chimney; it uses the manufacturer's listed PVC, CPVC, or polypropylene vent system with specific length, elbow, and termination limits. The chimney cannot simply be reused. The closet volume is about 60 cubic feet, far below the roughly 2,500 cubic feet that would be treated as unconfined space for a 50,000 Btu/h input at 50 cubic feet per 1,000 Btu/h. The louvered door to the hallway does not by itself prove adequate combustion air; two permanent openings sized to the code and the heater's input must be provided, or outdoor air must be ducted. Verify the manufacturer's clearances, condensate disposal, electrical supply, gas supply capacity, and vent termination location relative to windows, doors, and the condo property line. If the closet cannot meet clearances or vent length, the installation must be relocated or a different appliance selected.
3. What permit and licensing issues arise from the owner's plan to use a handyman and skip the permit?
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Replacing a water heater is plumbing work and normally requires a permit and inspection, even when the replacement looks similar. A handyman working for compensation generally cannot lawfully perform plumbing work that requires a plumbing license; the condo owner should use a licensed plumbing contractor. The condominium association may also require approval and proof of insurance before work begins. Skipping the permit creates several risks: the installation may not be inspected for T&P discharge, expansion control, combustion air, venting, and gas connections; the owner may have difficulty selling or insuring the unit; and the contractor may be exposed to penalties. The correct path is to pull the permit, submit the appliance listing and venting details, arrange inspection before concealment, and keep the inspection record with the unit. The permit requirement does not disappear because the old and new heaters are both gas-fired.