Originally Posted by 501s
I have a 2012 X-30 with the MV8 and my friend has a 2012 Moomba and the heater is much warmer on his boat then mine. He also has 2 pull out hoses while I only have 1.
If anyone has tips for improving the heat i'd also like to hear them.
The 2012 heaters were bad from the factory. There is a kit developed that moves your hot water supply port to a hotter portion of the engine, puts in a higher cracking thermostat, and moves your return port to spot to get more flow through the core. A couple of lessons that I've learned the hard way. Make sure when they cap your old supply port, they use a metal cap or plug, not rubber. It will split and cause you a world of problems. Also, make sure they update your software to increase the overheat alarm point. They supposedly have changed production to the higher Tstat, so all you need is the latest software revision. Mine now blows warmer air. It isn't as hot as what my car spits out, but it's a ton better than what it used to be.
As far as the OP, it looks like you've got an older boat, so this won't apply to you. Try to find your heater lines coming off the engine. When the engine's warmed up, feel the lines to see if one of them is warm/hot. If not, you're not getting flow to the core.
You can also look into getting a Y pipe to plumb your return line into your water pump inlet. This helps increase the flow through the core.