I have an electric water heater in the basement. The kitchen and bathroom are on the first floor. The hot water in the kitchen gets very hot, but the shower which is about 20 feet farther away only gets lukewarm. Any ideas ?
Re-adjust the anti-scald screws inside the shower faucet assembly.
Turn off the washing machine hoses using the faucets on the wall behind. It is possible for a defect in the machine to result in cold water crossing over into the hot pipe and spoiling a nearby shower.
Do not turn off any shower using the shower head or hand sprayer head. Always use the faucet(s).
The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.