Why does my boiler water keep going lukewarm?
Boiler temperature limits are often set too closely together, causing water to constantly fluctuate between lukewarm and too hot while forcing you to constantly fiddle with the dial. This poor design leaves sensors placed in dead ends where they cannot get accurate readings, preventing you from ever getting a stable hot water temperature.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Constantly fiddling with the shower dial to compensate for temperature fluctuations
- 2Adjusting the boiler temperature limits higher
- 3use a thermometer at a fixture
- 4install the temperature well right into the stream of hot water in the pipe
- 5cap or remove them
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“They all suck and always break!”source ↗
“The problem we've been having is that the hot water temperature turns lukewarm at the boiler low limit, which is currently set at 130, with a high limit of 140”source ↗
“the temperature constantly fluctuates between lukewarm and too hot, so you have to constantly fiddle with the dial.”source ↗
Where this came up
People with this problem also raised
- 4New water heater not getting hot enough
- 4Mini-split can't keep house warm when it freezes outside
- 3Why are my cold taps running tepid after a water heater service?
- 3Why is my apartment shower too hot and low pressure?
- 2Why is my water heater getting hotter than the thermostat setting?
- 3Why is my thermostat voltage fluctuating?