PW will not go above 150 degrees

Hey Wiz,
I have a Landa pghw 3000psi 4.8gal/min hot water pw and its only a year old. Yesterday I was using the hot water and I decided to check the psi and temp. The psi was fine but I had a problem with the temp. When I set the thermostat at 150 degrees the pw would go right to it. The problem is when I set the thermostat higher the temp. would not go over 150 degrees. What do you suppose the problem could be? I thought about possibly descaling the coils but since the machine is relatively new it shouldn't have to be done at this time. What do you think?
Thanks
-John-

------------------

I have seen this problem before. Change the fuel filter and clean the one inside of thje pump and change out the fuel nozzle inside thje burner. Also see if the fuel is on all the way at the fuel shuttoff valve on the tank. Also see if the fuel tank is clean inside.

------------------
Hotwaterwizard@aol.com If You have a problem with your machine, just ask I'll help if I can.