Guides · Season by season
What 115 degrees does to a water heater
A Valley summer changes what the heater is working with. Incoming water arrives warm, so the burner runs less, but the garage around it is hot, pressure in the system climbs, and relief valves and connectors made of rubber and plastic age faster. Summer is when a tired heater usually announces itself.
Warm water in
In summer the water arriving at the house is nowhere near cold. The heater has less work to do, which is why hot water seems to last longer in August than it does in January.
It also means a marginal heater can hide all summer. The same unit that coped fine in July is the one that runs out of hot water in the first cool week, because the temperature rise it has to produce suddenly doubles.
A hot garage
- Rubber supply connectors and washers harden faster in sustained heat
- Plastic components on fill valves, drains and pans get brittle over years of it
- Anything stored against the heater makes the space around it hotter still
- A heater in full sun through a garage door is working in worse conditions than one in a closet
Pressure, which is the real one
Water expands as it heats. If the house has a pressure regulator and no working expansion tank, that expansion has nowhere to go and the pressure in the system climbs every time the heater runs.
The temperature and pressure valve then does exactly what it was built to do and lets water out. People replace the valve, the weeping comes back, and the actual cause is never touched. That is why the pressure is worth reading at a hose bib before anything gets replaced.
What is worth doing in summer
- Measure the static pressure, and measure it again while the heater is running
- Check the temperature and pressure valve discharge for any sign it has been letting water go
- Look at the connectors on top of the heater for hardening or corrosion
- Flush the tank, because scale and heat together are what finish a tank
- Clear the space around the unit so it is not baking in its own heat
From the job log
Work we’ve done
Answers
Why does my cold water run hot in summer?
Because the supply line, and sometimes a stretch of it near the surface, is sitting in ground that is genuinely hot. It is normal here and it settles as the line runs.
Should I turn my water heater down in summer?
Some people do, and the water arriving already warm makes it less noticeable. If you turn it down, remember to look at it again when the weather changes.
My relief valve only drips in summer. Why?
That is thermal expansion, and summer makes it worse. It points at pressure and expansion rather than at the valve, which is why measuring first saves a repeat visit.
If you need this done
- Water heater repairNo hot water, water that runs cold early, noises or a leak? We find the real cause and give you an honest call on repair versus replacement.
- Water pressure and regulatorsPressure checked with a gauge, and regulators repaired or replaced when the house is getting more than the plumbing should take.
- Water heater installOld unit out, new one sized for your household, connected, tested and left to code. Gas or electric, tank or tankless.
- Where we workEvery town and ZIP across the Valley we cover.
In-home estimate
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We come out, look at the problem and explain what it needs before any work starts. For something urgent, calling is fastest.
Rather talk? Call or text (602) 833-4133.