Hot Water Flow Problem
Recently the flow of hot water in our 5th wheel has become restricted. The restriction is evident at all hot water faucets. The restriction occurs when we are hooked up to city water. The cold water flow is fine, no problem. We have a suburban water heater. I've drained and flushed the sediment out of the hot water tank. I've verified that my water filter is not the problem. I can't find any water line leaks. I've looked at the installation/maintenance manual and there is no help there. Does any one have any ideas or help you can give me? The next step that I'm planning to take is to disconnect the hot water line at the rear of the tank to see if there is a blockage.
Joe, since you notice the reduced flow at all hot water faucets, I would look for a blockage at either the inlet or the outlet fittings of the water heater. Depending on your particular setup, there may be one way valves located at this area.
If you have a wintering valve (or valves) there are some small passageways that can become obstructed by some very small particles.
You can try bypassing the water heater altogether, by connecting a temporary hose between the inlet and outlet fittings that lead into the tank. If the flow improves then you know where to look for the problem.
Had this problem once and found that the winter bypass valves (used to bypass the water heater when winterizing,) were half closed. I must have hit them when working under the sink. Some bypass systems use only one valve and a check valve. They are a disaster if you have hard water as the check valve often sticks because of mineral deposits, the flow is restricted. Camping World switched to selling the check valve type and Campers Choice still had the two valve system, last I checked. The check valve type is cheaper to produce, but they didn't decrease the price of the valve bypass kit. This is called "Value Engineering" or pay more get less.
This is an interesting observation as now Travelaire has switched back to the (plastic)three valve bypass system after several years of using one valve (brass) and check valve.(also brass)
The brass valves that have been around for the past three or four years are seizing(?) up continually and are such a pain in the *ss when you have to winterize. They just do not want to turn!
The cheap plastic check valves that are used in conjunction with bypass systems are the first likely suspect. My motorhome had them at both the cold water inlet (to prevent hot water from backing into the cold water lines) and at the hot water outlet to prevent antifreeze from getting into the tank when a single lever byass system is used. I got very little hot water flow when the rig was brand new. I replaced both check valves with "quality" brass valves when the unit was less than two months old. No problems since then.
A second can be caused by debris blocking the flow restrictors in the faucets. This affects both hot and cold water flow. I removed pieces of plastic pipe for a couple months after purchasing my motorhome. They would almost completely shut off the water flow. It's easy to remove them and see if you have any flow. In your case I doubt that this is the problem since you say that your cold water is OK
After posting my initial request, I did some further troubleshooting of my problem. It turns out that at the hot water outlet of the heater, there was a plastic check valve(backflow preventer) installed. This check valve was defective. I replaced it with a brass one and everything is back to normal.