Bulging hose from water pump to cold water line

When working behind the UDC on some new electrical modifications, I noticed the hose that is connected to the output of the water pump to a tee in the cold water line was bulging. This piece of hose looks identical in type to all the others behind the UDC and is about one foot long. I planned to change the hose out (it did have screw on type clamps). I didn't have any of the proper size hose at the time (1/2 inch inside diameter). Later in the afternoon, the water alarm for the basement went. Yes, I did install one as recommended on the Forum. I looked into what was going on and found that the hose had split. It has about a 1/2 inch long gash in it. After getting the shore water turned off fast, we made a trip to Home Depot in a hurry. I found Watts braided vinyl tubing that is 3/4 in OD and 1/2 inch ID. It didn't have any pressure specs but we found that it may be 150 PSI according to Watts web site. I replaced this one foot long piece of hose and hooked it all back up. This morning, I found a slight drip from one end and that the new hose seemed to be bulging a little. HELP! Has anyone had this or similar problem and what is the solution.

Tom, is there a restriction somewhere in the lines? It would hard for me to believe that the pump could create that much pressure. BTW, are you hooked up to city pressure at the same time?

I had talked to a service tech at Heartland today and had the same question about restriction or kink in some of the plumbing. I see no kinks in any hoses behind the UDC. This is a relative new rig and this is our first trip in it. We started on the trip on Labor Day and during the trip we usually use only the pump and not shore water until we stay somewhere for a few days. I found this problem after being on shore water for about a month. We never use both pump and shore water at same time - the pump does no good in this case. Other than this one piece of hose, all other pieces of hose are not bulging.

We have a pressure regulator on the hose, 60 lbs. psi.

It may not be the cause, but if the tee you mentioned is an original plastic PEX fitting, the orifices are smaller than similar sized brass ones. It might also have some debris stuck in it. If you can work with PEX fittings, you might want to replace it.

Plugged or kinked lines should not cause "bulging". The maxiumum pressure that your lines should see is either what the pump pressure switch is set to, or what the city water pressure is (60 psi in your case) Some hoses are constructed in two layers, with a reinforcing mesh in between. If the inner layer develops a pin hole or has one as a manufacturing defect, then the outer layer sees the pressure, bulges and fails soon after. I don't know why your new hose is bulging. They do expand a little initially, but there should be no noticeable local bulging. Braided vinyl hose should easily take the sort of pressures we see in RV's as long as you protect against pressure spikes in the campground supply by using a proper pressure regulator. I'd monitor it carefully, and shut off your city water if leaving the trailer unattended.

Unless you have a faulty pump. I don't know if it's possible for one to go into an overpressure condition since they're designed to shut off at 45 psi. This is from the Shur-flo website and the couple of pumps I looked at have the same pressure ranges.

One piece of OEM flex hose being defective I can understand, but to get the same condition with a new section??

http://www.shurflo.com/files/RV-Product-Data-Sheets/Classic-Series-Pumps/Classic%20Pump%20-%20pds-2088-422-144_444_.pdf

If I remember correctly...HL recommends a max pressure of 55#. I could be wrong....but that is what our Watts regulator is set at.

Do you have any idea where you might have read this piece of information? We looked at the original hose and it said it was for "low pressure" the one we replace it with is for 150# pressure(I don't consider that low pressure). We have our regulator set for 60#. HL didn't mention any number for pressure when we called.

We sure are happy we invested in the water sensor.....................

Check out the information in this thread: //heartlandowners.org/showthread.php/14883-Water-pressure-maximum-in-Bighorn

To have a second hose bulge makes me wonder if you have a heat source nearby that would weaken the hose. We use that type hose on sprayers and other applications and never see bulges. One hose could have been a factory defect. The second would really be odd if it was.