Plumbing Resources

California law requires two seismic straps on every storage-type water heater — one within the upper third of the tank, one within the lower third (minimum 4" above the controls). This applies to both gas and electric units. A missing or loose strap is one of the most common reasons warranty inspectors deny water heater claims in California.

Every water heater must have a Temperature & Pressure Relief (T&P) valve. Its discharge pipe must run downward to within 6"–24" of the floor, terminate outdoors or at a drain, use approved metal pipe (never plastic), and have no shutoff valve between the T&P and the atmosphere. An improperly piped T&P valve is a major code violation — and a dangerous one. Excess pressure with nowhere to go can cause a tank explosion.

California law makes it unlawful to install, remove, or replace a water heater without a permit. Work done without a permit — even if it looks correct — is technically a code violation. Home warranty companies use this to deny claims, and it can also create problems when selling your home. Always require your plumber to pull a permit and schedule the final inspection.

A sediment trap (drip leg) must be installed on the gas supply line, downstream of the shutoff valve and as close to the water heater inlet as possible. It catches moisture and debris before they enter the burner. Many older or DIY-installed units in Fresno are missing this component entirely — a straightforward code violation that gives warranty companies grounds to deny gas-related water heater failures.

Gas water heaters installed in garages must have the pilot light and all burner controls elevated at least 18" above the garage floor. This prevents ignition of gasoline vapors from vehicles. Heaters sitting directly on the garage floor are a code violation and a fire hazard — and an instant warranty denial trigger if a service tech spots it during a claim visit.

When a water heater is installed in an attic, on a raised floor, or in any location where a leak could damage the structure below, a watertight drain pan (min. 1.5" deep) with a ¾" drain line to an approved location is required. A water heater sitting without a drain pan in an interior closet or attic is a code violation — and if that tank leaks, warranty coverage may be denied and you could be left with a major water damage bill.

Gas water heater flue vents must use double-wall metal pipe where they pass through ceilings, walls, or floors. The vent must maintain clearance from combustibles, terminate a minimum of 12" above the roofline, and exit with an approved vent cap. Single-wall vent pipe through a wall or ceiling is a code violation — and a carbon monoxide risk. Improper venting is also a frequent home warranty denial reason.

California's Title 24 Energy Code requires insulation on the first 5 feet of hot and cold water pipes connected to the water heater. This reduces standby heat loss and is an energy code compliance item. While less commonly cited by warranty companies, it's flagged during permit inspections — and missing insulation can result in a failed final inspection, meaning your permit is never closed out.

Union fittings are required on both the hot and cold water connections of a water heater to allow the unit to be serviced or replaced without cutting pipe. Many inspectors also require a union within 12" of the T&P valve so the valve can be easily removed and replaced without disturbing the discharge line. Missing unions are one of the most common items flagged during re-inspections and can require significant rework to correct after the fact.

If your home has a pressure regulating valve (PRV), check valve, or backflow preventer — which most Fresno homes do — it creates a closed system. When water heats up, it expands and has nowhere to go, causing pressure spikes that can damage the water heater, pipes, and fixtures. California requires an approved thermal expansion tank on all closed systems. This is frequently missing on older installs and is a common reason home warranty companies deny water heater claims.

Where copper pipe connects to steel or galvanized fittings on a water heater, a dielectric union is required to prevent galvanic corrosion — an electrochemical reaction that rapidly deteriorates both metals. Without them, the connections corrode from the inside out, causing leaks within a few years. Dielectric unions are inexpensive but commonly skipped on DIY installs and even some contractor work. Inspectors flag them on all permitted replacements.

The flexible gas connector between the gas shutoff valve and the water heater must be a listed appliance connector no longer than 3 feet. Using corrugated stainless steel tubing (CSST) as the flex, running the connector through a wall, or reusing an old connector are all code violations. Connectors must also be installed without kinks, sharp bends, or contact with the flue. An improper or over-length gas flex connector is a safety hazard and a guaranteed fail on any inspection.