I have a Delta shower valve that doesn't put out enough hot water. I turned the stop all the way up, but the shower water is only warm. Is there a way to increase the temperature above the "maximum"¿

when you turn the valve all the way to its hottest setting, leave it running cool and turn on another faucet or two to straight hot at the same time. what happens ?
trying to figure out if it a valve problem or a hot water delivery problem.

When I turn on the hot water in sink when the shower is running, the temperature in the shower stays the same, but the hot water in the sink gets hot.

Probably a defective balancing spool in the cartridge.

A little more background information. This a new home and there are 2 different showers with the same problem (same Delta valves that won't get hot enough). There's another shower with a different valve that doesn't have this issue. I tried turning the stop on the delta valves higher, but it is a the maximum setting and the water still isn't hot.

this is puzzling. both valves have the limit stop adjusted to the hottest setting yet both valves don't get hot enough but at the same moment the sinks get hot ??
don't be angry but are you absolutely sure the limit stops are adjusted to the hottest setting?
my only other thought is that the balancing spools are stuck and need to be shaken loose.
has the hot water to one or both EVER been adequately hot or have they always been like this ?

It is a new house and it has been this way since day 1. The temperature adjustment knob is maxed out, I adjusted it in the other direction and the water gets colder. Is there a way to adjust the valve past the hottest setting?

there are a couple of different types.
see here. [homeguides.sfgate.com]

sometimes you can just remove the adjustment part and the stem will turn further. (sometimes).

The one I have looks like this and the stop cannot be removed.

[www.amazon.com]

[worldwide.deltafaucet.com]



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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

The problem is that the rotational stop is fully rotated to the hottest setting, but the shower isn't getting hot.

INSIDE the 'trim' is an additional part which physically limits the 'travel' of the external rotational stop/handle.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Yes, the internal piece is rotated to the hottest setting, but the temperature doesn't get hot, only warm.