The T&P (Temperature and Pressure) relief valve is the safety device on every water heater — including Westinghouse. Opens to relieve pressure if tank pressure exceeds 150 PSI OR tank temperature exceeds 210°F.
Westinghouse T&P specs
- ¾" NPT male thread
- 150 PSI / 210°F rating
- Universal — Watts, Honeywell, Cash Acme equivalents fit
Semi-annual test
- Position bucket beneath discharge tube
- Lift the lever briefly
- Water discharges through tube under pressure
- Release lever; discharge should stop completely
- Drips after release = failed valve, replace
When to replace
- Drips or weeping after lever test
- Visible discharge without testing
- Age over 5-7 years (preventive)
- After plumbing freeze damage
Replacement procedure
- Power off at breaker; verify with voltage tester
- Close cold water inlet shutoff
- Open hot tap downstream to relieve pressure
- Catch residual water with bucket
- Disconnect discharge tube
- Unscrew T&P from tank port (large wrench)
- Apply Teflon tape (3-4 wraps) to new valve threads
- Install new T&P, hand-tight plus 1-2 turns
- Reconnect discharge tube
- Open inlet; verify no leaks
- Restore power; test operation
Discharge tube requirements
- ¾" copper or CPVC
- Continuous downward route (no traps)
- Terminate within 6" of floor
- No cap on discharge end — must be open
- Terminate in same room as water heater
Cost
- Universal T&P valve: $15-25
- Plumber labor if hired: $60-120
Critical: never plug or block T&P
If T&P drips frequently, address the cause (thermal expansion → expansion tank; high pressure → check pressure regulator) rather than disable the valve. T&P is the primary safety device protecting against steam-flash events.
Bottom line
Universal T&P valves fit Westinghouse. Test semi-annually. Replace at first sign of drips. Never block or plug — fix the cause of discharge instead.