Hot Water Issue

[WeGoFar]

Hello All
I am looking for some advice trouble-shooting a hot water problem. I have a 2007 CC Allure 470. It has a Hydro Hot system for heating the water. A Diesel boiler (in case I got the name of it wrong). The diesel starts up and we get hot water, but it takes much longer than it used to. Also, the shower seems to get less hot water than either of the sinks. I notice that the hot water flow in the sinks is rather low as compared to the cold water flow. I was thinking that the low flow of the hot accounted for the fact that the shower stream does not get as hot as it used to (Hot and cold mix in the showerhead. Not separate controls).
Could it be a water temp control gone bad? Any ideas what could restrict hot water flow, but not restrict cold? I have checked and cannot find any water leaks. Also, I do not think there is air in the system (Water does not spray or spurt when I turn on a faucet.)
Any ideas for waht to check would be appreciated.
TIA
Bruce

[Jim_HiTek]

Is it cold where you are...that's one thing that makes it come out of the taps cooler.

Do you also have an electric element? And is the switch for it ON? I ask because some people accidentally turn it off and then wonder why their shower isn't as hot as it use to be. That's if you are the conservative type and only turn on the burner when needed, and don't leave it on all the time.

[WeGoFar]

Jim_HiTek
Depends on what you mean by cold. I live in Boulder City NV. We think it is cold when it is below 50 in the morning. I don't think that is the problem.
Yes there is an electric element. It is turned on all of the time and there is a limited amount of hot water. We always turn on the diesel for showers and then turn it off.