Hello I have a question about my shower faucets. I installed two of them new about 8 months ago and they worked fine for about 6 months. I had more than enough hot water. About 2 months ago they started to just put out warm water. I have plenty on hot water from the hot water heater and when in the shower if someone turns on a faucet or flushes the toilet the shower will put out very hot water for a few seconds then goes back to warm water. I had adjusted the scald guards to the hottest settings when I installed the faucets.
I put new cartridges in today and still only warm water.
They are delta faucets.
any suggestions on where to look now?
Thanks

how do you know you have plenty of hot water from the water heater ?
when the showers are running warm, do the faucets still have hot water? both running together..

While you were replacing the cartridges, did you have someone briefly turn on the water to flush out any debris that builds up under those cartridges. If not pull the cartridges and flush for a few seconds then reinstall the cartridges. You must place your hand over the valve body too prevent making a mess while flushing. If you also place a wash cloth over it you can see the debris. It is better to use the main shut off valve because angle stops will often leak if they have not been exercised for a long period of time. This is one reason why Plumbers exist. Many homeowners do not know about these things. Good luck.