Surging Hot Water

Nomad

Anyone else find this - If you run just the hot water - filling the sink for instance - you get a lot of surging from the pump. If you crack open the cold water even just a little bit it evens out and you get a nice steady flow?

jkjenn

PXLated said:

61 views so far - None of you have found this?

Maybe? It never really stuck out to me. It will be a few months before I can check.

Verna

PXLated, my tank is empty right now (no sense in filling it if I'm moving tomorrow).. I'll try tomorrow after I get set up. 

Nomad

Okey dokey :-)

ScottG

I notice a bit of surging from the pump, but never paid attention to whether it was greater from the hot tap. I suspect it has something to do with pressure differentials resulting from the extended length of plumbing the hot water has to pass through (compared to the cold). If that were the case, cracking the cold faucet might alter the system pressure enough to smooth out the flow. Air trapped in the HW tank or lines might contribute, as well.

Is this a new phenomenon, or something you have only recently decided to ponder?  

Nomad

Something I've noticed before but not paid much attention to as I'm usually running a combination of both. Wanted extra hot water in the sink so the surging was pronounced. Cracked the cold and big difference. Cold by itself is fine so it's a hot water thing.
Not really a new observation just a more focused one, a curiosity :-)

DurangoTaB

I have a new routine before we leave the house, and that is to "prime" (fill) the lines...and Alde tank (2gals), thus avoiding 1) draining our 5gal FW tank, 2) waiting FOREVER for the hot water to warm up, and 3) minimizing any surging/cavitation (what a pump does when it sucks air) at the camp site.  Is your surging just at first...or all the time?  

ChanW

That's interesting PXL.

We do get weird flow rates with the pump now and then, but I've never noticed any pattern to it. I'll have to check.

Something that comes to mind, now that y'all are taking about it, is that Alde recommends draining the hot water 'tank' every month or so, and refilling, to restore the air cushion to the system. It makes sense, and might have something to do with the phenomenon you're describing.

Nomad

J.D. - It's not all the time. But I rarely run just hot. Haven't really noticed a pattern. Being full-time, my tanks are in constant flux as far as full or not. Never completely empty. Since I carry extra water, they're probably never below 1/3-1/2.

ChanW - Hmmmm - My manuals are packed away - Where's the drain?

jkjenn

DurangoTaB said:

I have a new routine before we leave the house, and that is to "prime" (fill) the lines...and Alde tank (2gals), thus avoiding 1) draining our 5gal FW tank, 2) waiting FOREVER for the hot water to warm up, and 3) minimizing any surging/cavitation (what a pump does when it sucks air) at the camp site.  Is your surging just at first...or all the time?  

This is an excellent idea. It would give you a little bit more than what your freshwater tank could hold. To prime, do you just open the faucets until the water runs and warms up?

DurangoTaB

I plug the hose in at the house, then fill the lines before departing...I don't heat up til we get to the camp,site.  With the tank full, and heating with propane, it only takes 15-20 minutes...and no gurgling or surging.  Now...if I could get all the snow off... ;-)

ChanW

PXL,
That would be simply draining the water lines till empty. The drain valves goes through the floor off the PEX line near the Alde.

I don't know what your plumbing looks like, but the best way to do it would probably be to open both water line drain valves (going through the floor), open the hot & cold taps in the kitchen to let air in as it drains.

That way the lines will drain out all the way through the Alde.

Just guessing without seeing your pipes...

Edited: to say drain both hot & cold lines...

PXLated said:

ChanW - Hmmmm - My manuals are packed away - Where's the drain?

ScottG

In addition to the hot and cold drains, my 2015 S also has a separate drain for the Alde HW tank. It's in the CW line feeding the Alde, and has a yellow flap-like handle. If you pull the handle straight up (perpendicular to the pipe) the tank will drain to the outside just below the valve.

The US/Can Alde manual calls this the "combined safety/drain valve" and indicates it's use for draining the tank to maintain the air cushion Chan mentioned previously. It's unclear if just opening the regular hot and cold drains would serve the same purpose, but I'm suspicious there might be a backflow preventor in the cold line that might impede draining of the tank.