12v water pump acting up

[modmidget]

Our motor home is just over a year old and has a Shurflo Model 4008-101-E65 water pump installed. A few days ago when I turned on the faucet at the kitchen sink we had good water pressure for a few seconds then the stream of water slowed way down. I could hear the water pump running and when I turned the faucet off it took 15 to 20 seconds (or more) for the pump to bring the water pressure up. Once the water pressure is up the pump does not run from time to time, so I'm pretty sure it's not losing pressure. We also lose water pressure at the bathroom basin and the shower.

[modmidget]

Got the motor home back from the shop today. For those of you who said "plugged water line from the tank", you got it right. It wasn't the screen filter at the pump, it was plugged where the water line attaches to the tank. $95.00 fixed it. Next time I'll blow the line out myself. :S

[ksg5000]

Water pumps are pretty cheap - RV techs time is worth more than messing around with water pump - suspect they will replace.

[modmidget]

This morning I was going through some of the papers I got when I bought this motor home. In the papers I found the $4000.00 extended warranty we bought the day we bought the motor home. I took the membership card to our local (mom & pop) RV dealer and they confirmed they do work for my insurer (Protective ExtraRide). I've made an appointment to take the motor home in next Tuesday. I'm not gonna wear myself out trying to solve this water pump problem since I've already paid for the warranty.

When I described the water pump problem to the owner of the dealership he said it is probably the pump.

[MARKW8]

MEXICOWANDERER wrote:
An awful lot of guesswork here. Go to the RV place get a dummy fitting, hose barb and about four feet of 1/2 clear hose and a clamp. Yep, it's for substituting a dummy feeder to the pump. A small bucket filled with water will supply the water. You're going to find out in a heck of a rush where the problem is once you click on the pump switch.

Thanks, I needed that. Your post was a slap upside the head for me. It helped me find the problem on my new Redwood I'd been chasing with the same problem.

To the OP, I have the same pump as you and I started following this. I dout you hurt the pump, they can run dry and are thermally protected. My problem was multiple leaks on the suction side. Two I'd found. The above helped me find the third. All because of bad workmanship.

Mark

[MEXICOWANDERER]

An awful lot of guesswork here. Go to the RV place get a dummy fitting, hose barb and about four feet of 1/2 clear hose and a clamp. Yep, it's for substituting a dummy feeder to the pump. A small bucket filled with water will supply the water. You're going to find out in a heck of a rush where the problem is once you click on the pump switch.

[modmidget]

The pump does have a screen filter on the side of the water line. I removed it and checked the screen. It was clean. Then I replaced the 10" filter in the WaterPur canister. I'm thinking I should probably take the screen filter off of the water line again and 'maybe' blow some air back through the line to the water tank. I won't have access to the motor home again until Monday or Tuesday, so it'll be a few days until I can work on it again.

[beemerphile1]

The pump is fine. You have a restriction in the line, a filter maybe? Some pumps use a metal screen filter mounted on the side of the pump. With a line restriction you will get pressure initially but little flow. That is exactly what you described.

[ReelTime]

What Swamp Man said, X2 Looks like you need another pump.

[Swamp_Man]

Sounds like your pump was damaged when it ran dry. Motor may have overheated and runs fine for a short time then starts slowing down. This causes the drop in pressure about the initial 20 seconds of pressure.

[modmidget]

Yes, same issue with hot and cold water and all outlets.

I don't think there is a water heater bypass installed. If there is I wouldn't know where to find it.

[ksg5000]

Same issue with hot and cold water? Same issue at all outlets or just shower? Do you have a water heater bi pass installed?

[modmidget]

I checked the filter screen on the pump inlet. It's clean. Then I hooked up to city water and opened all of the hot water faucets. I did get some air for a couple of minutes but that didn't solve the problem. After disconnection city water and trying the pump again the stream of water was good for about 20 seconds then it slowed down to a trickle again.

[BruceMc]

Sounds like the inlet to the pump may be clogged.. Pull the line off the inlet side of the pump, you should have a filter screen.

[OnaQuest]

The hot water tank will hold SIX gallons. Is it full?

With the faucets closed and the pump pressure up, open the pop-off valve on the water heater. Does water come out under pressure? Does it also drop off to a trickle?

You also may need to open your gravity fill port, if you have one. Maybe the fresh water tank vent is plugged.