Technical comments/questions regarding water accumulator

SkyBound · 08-18-2013, 08:51 AM

I recently installed a Shurflo 24oz accumulator in my fresh water system. The trailer's water system was completely drained and dry when I did the mod. Once completed, I filled the fresh tank to 1/3 and turned on the pump. Once the air purged out of the cold system, the accumulator worked really well. The water could run for about 10 seconds and then the pump would kick on for 5-10 seconds and shut off. Perfect. I then drained the lines and tank and called it a day.

This past camping trip, after filling up and purging all the air out of the hot and cold lines, the water would flow for maybe 3 or 4 seconds and then the pump would kick on for about the same. I was only able to get maybe half a pint of water out of the kitchen tap before the pump came on. I was puzzled, and checked the pressure of the bladder - it was good at 25psi. No leaks either.

First of all, you guys with the same accumulator - does this seem like normal volume for this thing? I know it's small, but I expected maybe just a bit more out of it, like the first time I tested it. Yes? No?

I thought about things long and hard and I have one theory. When I first tested it, I only used the cold water system, meaning the hot water tank was full of air. I never did purge that air out. I'm thinking that maybe the hot water tank was acting like an accumulator? The pump would push water towards the hot tank, but with nowhere for the air to go it pressurized, met the target pressure at the pump and turned off... Then the compressed air in the hot tank helped push cold water, overall increasing the output of the accumulator. Can anyone verify that this is feasible?

**Crabman** · 08-18-2013, 04:54 PM

I have that same setup and will try it when possible to see the time between cycles, but it is a small tank.

**norty1** · 08-18-2013, 07:41 PM

I would do another test, I think you may be off on a tangent. When my pump is on and the system drained, It will run until the hw tank is full if a hw faucet is opened.

Another thought is that some accumulator tanks have an air charge that may need to be checked and properly drained

tnchuck100 · 08-19-2013, 04:30 AM

Your theory of the empty water heater acting as an accumulator is accurate. I have the same accumulator you have and yes, about a pint is what you get before the pump comes on. Only about 2/3 of the accumulator will have water. The remainder is the compressed air. The do make larger accumulators (1 - 2 gallon) but due to space restrictions it would not be practical in my case. The sole intent of the accumulator was to stop the rapid on/off cycling of the pump.

glsimms · 08-21-2013, 09:27 PM

Do you guys have any advise or "how to" add an accumulator???

tnchuck100 · 08-22-2013, 04:36 AM

Quote:

Originally Posted by glsimms

Do you guys have any advise or "how to" add an accumulator???

Place it anywhere that is convenient to connect to a cold water line that is after the pump. Most of the time they are positioned right next to the pump but that is not required. There are usually two ports on the accumulator to allow it to be placed in line. If space is a problem you can plug one port an connect the other to a line going to a tee anywhere in the cold water line after the pump. Hope this helps.

SkyBound · 08-22-2013, 08:39 AM

The accumulator has threaded ends, so your local RV store can sell you the fittings required. You may also need a length of 1/2 inch water hose, and use worm clamps to attach the fittings into the hose. It's pretty simple, straight in, straight out somewhere after the pump. In my case, I had to add a 90* elbow off the pressure side of the pump just for space reasons.

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