Hot Water Flow Inconsistent w/ Pump

[Brandt51]

I've searched and I'm not sure if my problem is the same as others.

When NOT hooked up to city water, my hot water flow is inconsistent and spurts a lot, like there's an air pocket built up in the lines or something. Only hot water from the kitchen sink, bathroom sink and shower. Cold is fine. Also, the pump runs for a long time after water is shut off.

Any ideas or where to look?

Thank you!

[scottxpc]

Check your hot water bypass sounds like it's in bypass mode

Originally Posted by Brandt51

I've searched and I'm not sure if my problem is the same as others.

When NOT hooked up to city water, my hot water flow is inconsistent and spurts a lot, like there's an air pocket built up in the lines or something. Only hot water from the kitchen sink, bathroom sink and shower. Cold is fine. Also, the pump runs for a long time after water is shut off.

Any ideas or where to look?

Thank you!

[Thom]

Burp your water heater tank, open the pressure relief valve until water comes out. For safety reasons, turn it off and let it cool down some first.

A second item to check is your outdoor shower hook up if you have one, make sure both valves are closed when the hose is not in use. If these valves are left open, it will cause the hot and cold water to mix there and travel throughout your whole system.

[joebedford]

I replaced my water pump to eliminate symptoms like that.

[persistent]

I replaced my water pump because of symptoms like that, but both hot and cold water were pumping air. (Air in the lines causes the spurting as it passes through the faucet valve.) The pump chamber had a crack on the low pressure side.
Air has to be getting in some how. If it is truly only hot water, there may be air in the hot water tank. The air will eventually be forced out and the spurting will stop spontaneously. Every time you drain the hot water tank there will be more air trapped in the tank when you seal it and start pumping again. Air in the tank causes the pump to run longer after shutting off the faucet. The less the air, the shorter the after run.

[Brandt51]

All suggestions followed, thank you. Still not fixed and has worsened. Spurts air in hot and cold (maybe it did before?). Pump still will NOT shut off. Any ideas? Cracked supply line to the pump inlet?

[franktafl]

I had a bad pickup in the fresh water tank. Air when it gets down to 1/4 tank.

[John_C]

Originally Posted by Brandt51

All suggestions followed, thank you. Still not fixed and has worsened. Spurts air in hot and cold (maybe it did before?). Pump still will NOT shut off. Any ideas? Cracked supply line to the pump inlet?

Hi Sam,
I am not really familiar with the Dutchman family of trailers yet; however, I have a few questions. When not connected to "City Water", the water must come from the Fresh water tank. Assuming you checked the before mentioned items from the group, I have to ask:
1) How much water is in the fresh water tank?
2) Have ALL bypass and winterizing valves been closed/set to non-bypass mode; My cruiser by-pass valves had to be set just right to prevent any bypass?
3) Do you see any leaks or drips anywhere; the suction side may not show a large leak?
Good luck...

[joebedford]

Originally Posted by Brandt51

All suggestions followed, thank you. Still not fixed and has worsened. Spurts air in hot and cold (maybe it did before?). Pump still will NOT shut off. Any ideas? Cracked supply line to the pump inlet?

I solved exactly the same symptoms as you be replacing the pump. Same model so it just snaps in - didn't have to change any fittings or pipes. $92 on Amazon.

[Brandt51]

Hello,,

I replaced the pump and no change. I’ve had this issue before, but far worse when the ounpninket fitting was cracked on the little filter piece, but it all looks good. And the pump would still turn off with no demand.

Fresh water tank is full (140 gallons). Bypass and winterizing valves set to norm. The pump switch light is dimmer than the other switches, but I don’t that’s an issue. I’m going to check the amp draw regardless. I’m going to go back into the basement and see what I can find.

[John_C]

Originally Posted by Brandt51

Hello,,

I replaced the pump and no change. I’ve had this issue before, but far worse when the ounpninket fitting was cracked on the little filter piece, but it all looks good. And the pump would still turn off with no demand.

Fresh water tank is full (140 gallons). Bypass and winterizing valves set to norm. The pump switch light is dimmer than the other switches, but I don’t that’s an issue. I’m going to check the amp draw regardless. I’m going to go back into the basement and see what I can find.

Good going Sam,
Having worked with many Aircraft Mechanics over the years, sometimes we get hooked on the problem and overlook the obvious... I had to ask.

In any case, it definitely sounds like there is an air leak on the suction side (cracked or lose fitting, hose, or valve) or the pump is cavitating and creating air at the impeller, due to an obstruction on the inlet side (hose, valve, pick-up, fitting, or filter [if one exists]). There may be a kinked or twisted hose that once the water is sucked by the pump, closes off more to create a blockage. I actually saw this on an aircraft's auxiliary engine once and when the engine was loaded you could see the line squeeze down, shutting off fuel and killing the engine.

You replaced the pump so, it is unlikely that the new pump is the problem. Maybe you can see something if someone turns on the water while you watch the different fittings and hoses, again, maybe.
Good luck again...

[Brandt51]

Originally Posted by Brandt51

Hello,,

I replaced the pump and no change. I’ve had this issue before, but far worse when the ounpninket fitting was cracked on the little filter piece, but it all looks good. And the pump would still turn off with no demand.

Fresh water tank is full (140 gallons). Bypass and winterizing valves set to norm. The pump switch light is dimmer than the other switches, but I don’t that’s an issue. I’m going to check the amp draw regardless. I’m going to go back into the basement and see what I can find.

Also. No leaks.

[John_C]

Originally Posted by John_C

Good going Sam,
Having worked with many Aircraft Mechanics over the years, sometimes we get hooked on the problem and overlook the obvious... I had to ask.

In any case, it definitely sounds like there is an air leak on the suction side (cracked or lose fitting, hose, or valve) or the pump is cavitating and creating air at the impeller, due to an obstruction on the inlet side (hose, valve, pick-up, fitting, or filter [if one exists]). There may be a kinked or twisted hose that once the water is sucked by the pump, closes off more to create a blockage. I actually saw this on an aircraft's auxiliary engine once and when the engine was loaded you could see the line squeeze down, shutting off fuel and killing the engine.

You replaced the pump so, it is unlikely that the new pump is the problem. Maybe you can see something if someone turns on the water while you watch the different fittings and hoses, again, maybe.
Good luck again...

Sorry... I'll drop it.

[Brandt51]

Good deal. When I get home I’ll look for kinks and brakes on the supply hose. Hopefully the 3200isntbtoo hard to get to the freshwater tank.

[sundancer 87]

Originally Posted by John_C

Good going Sam,
Having worked with many Aircraft Mechanics over the years, sometimes we get hooked on the problem and overlook the obvious... I had to ask.

In any case, it definitely sounds like there is an air leak on the suction side (cracked or lose fitting, hose, or valve) or the pump is cavitating and creating air at the impeller, due to an obstruction on the inlet side (hose, valve, pick-up, fitting, or filter [if one exists]). There may be a kinked or twisted hose that once the water is sucked by the pump, closes off more to create a blockage. I actually saw this on an aircraft's auxiliary engine once and when the engine was loaded you could see the line squeeze down, shutting off fuel and killing the engine.

You replaced the pump so, it is unlikely that the new pump is the problem. Maybe you can see something if someone turns on the water while you watch the different fittings and hoses, again, maybe.
Good luck again...

The 12 volt demand pump can't cavitate because they don't have an impeller. They have three or four diaphragms, depending on the model. They are designed to run dry and have a limited lift which means they don't need to be primed.

[John_C]

Originally Posted by sundancer 87

The 12 volt demand pump can't cavitate because they don't have an impeller. They have three or four diaphragms, depending on the model. They are designed to run dry and have a limited lift which means they don't need to be primed.

Good to know, thank you, but we could still be looking at an obstruction or leak, wouldn't you think?

[Brandt51]

Originally Posted by John_C

Good to know, thank you, but we could still be looking at an obstruction or leak, wouldn't you think?

John, I like your suggestions and gives me a direction to go. Regardless of the technicalities of pump operation.

[sundancer 87]

Originally Posted by John_C

Good to know, thank you, but we could still be looking at an obstruction or leak, wouldn't you think?

Absolutely, anything is possible with these things.

[dsol]

Crazy idea but since it is only the hot water heater and only when using the tank maybe there is an obstruction in the water heater that gets overpowered by the pressure from City water but not by the pump. Could you try with City water but barely turn on the water and see if you have similar symptoms with the hot water when there is little pressure. Honestly, I am not optimistic because pump pressure is still likely pretty good but you never know.

[Brandt51]

Originally Posted by dsol

Crazy idea but since it is only the hot water heater and only when using the tank maybe there is an obstruction in the water heater that gets overpowered by the pressure from City water but not by the pump. Could you try with City water but barely turn on the water and see if you have similar symptoms with the hot water when there is little pressure. Honestly, I am not optimistic because pump pressure is still likely pretty good but you never know.

It's not just hot water, I was wrong with that finding. It's both hot and cold. I'm going into the basement this weekend to check it out. I'm hoping it's a collapsed or kinked intake hose.