Please help. I have a brand new New Yorker boiler with NO separate hot water heater. My settings are as follows. Start temp 140 HL 180 HL dif 10 LL 160 LL diff 10. Showers start out scalding hot and quickly go luke warm. If I wait long enough it will get warm again but sometimes end up with cold water. I have watched the boiler thermostat while my daughter is in the shower and this is what happens. Anytime I check the boiler temp starts at 170ish. after starting the shower within a minute or 2 the temp is down to 150. The boiler does not fire until it reaches 140 and the temp continues to decrease down to
120 or so. I did try to set the low limit diff to 15 but I got an even colder shower.I have had this type of system for 20 years and never had a cold shower. The only cold water intake value is what appears to be a normal shut off. I have turned this down slightly to allow less water into the system at one time with out much luck. My shower head is an eco head and was fine with the last boiler so I don't feel that is the problem. I do not have a mixing value. The installer said the mixing value wouldn't solve my problem. He recommended a new shower head and scolded me for not getting the water heater that he suggested. As I said for 20 years and 3 homes I have never had a hot water heater and always had endless hot water.