seaward water heater exchanger hookup

[galynd]

I have a seaward s700 water heater which is hooked up to 120 v electric but has never been hooked up to the heat exchanger. It has one continuous hose that leads to each of the heat exchanger fittings on the rear of the water heater to keep it clear of trash, etc.
This weekend I decided to finally hook it to the motor exchanger to have hot water when motoring. I disconnected the hose from one fitting and tried to blow through the exchanger to assure it is clear. I couldn't blow through it. I also tried to blow the other direction and again nothing. It appears to be stopped up where the motors coolant should flow through the water heater exchanger. The hose is clear.

Am I overlooking something? Why can't I blow through the water heater exchanger?

Thanks, Greg.

 

[Stu Jackson]

It might take much more pressure than you're able to produce. Hook it up and see if it works.

 

[prh77]

Actually, the fresh water pump on our little engines only puts out about 5 psi. So if you cannot blow through the hot water heater with lung power, you have a problem. Perhaps compressed air ?

 

[kloudie1]

Does it have a tempering valve across the engine water connections? If so could be a stuck valve element..remove the tempering valve and see if the tube is clear.. clean the valve.. If no tempering valve, there is some kind of blockage .. Seems like the hose would have kept it clear , but the hose may have been put on after the mouse crawled in ! (or the mud dauber filled the tube with mud and spiders)To clear it you can try some 10 gauge multi-strand wire pushed through .. followed by a flush with a water hose to blow through. Don't think I'd use compressed air except at very limited pressure..