Hi Steve, Thank you for your question. Our faucets are designed to function with working water pressures of 20 to 100 PSI. Thanks, Dave

Hi Seabird, Thank you for your question. It sounds like the rotational limit stop on the cartridge is missing or not adjusted correctly. The rotational limit stop(RLS) is the 2 brass arms underneath an o-ring on top of the cartridge used to set the max hot water temperature on the faucet. The cartridge/RLS should look like the 2 pictures attached below. I have also included a link to the manual for the model PTT188742 which will cover how to make the RLS adjustment. If parts are missing the entire RP70583 cartridge will have to be replaced. Thanks, Dave http://www.peerlessfaucet.com/customer-support/find-repair-parts/documentation/ptt188742.html?document=mi&documentIndex=0

Hi Jen, Thank you for your question. Your model PTT188742 faucet comes equipped with a rotational limit stop that allows you to set the max water temperature for your faucet. I have attached the instructions on how to make this adjustment to raise the water temperature below. You will have to remove the handle and trim sleeve to make this adjustment. Thanks, Dave