Can a well cause hot water problems?

[Banjo Bud]

I had city water for years. Never had a hot water problem. I could take a shower while the washing machine was filling or someone else was washing dishes. Any two or three things could be going on at once without any problem. 2 years ago I put a shallow well pump in. The calculated output of the pump is 7 GPM. Seems like plenty. But now whenever two things are going on at the same time, like shower and washing dishes or flush a toilet, the shower goes cold. What could be the problem? I have a CSV.

 

[Reach4]

What is the pressure while running the tub or shower cold before flushing that toilet? What is the pressure while that toilet is filling adding the additional usage?

 

[Sponsor]

 

[Bannerman]

This situation is often a result of how the home is plumbed. Often, too many fixtures are supplied from a pipe that may be too small to deliver sufficient flow to multiple fixtures at the same time.

The CSV provides benefit as it will regulate the flow rate from the pump to attempt to maintain constant downstream pressure up to the pump's maximum flow rate (7 GPM).

Although 7 GPM may be more than sufficient for the CSV to provide sufficient flow at consistent pressure to the multiple fixtures you are attempting to run at the same time, if the pipe size after the CSV is too small so a bottleneck is created, those fixtures will be competing for flow through the common supply line which will result in less pressure and lower flow to each fixture.

 

[2stupid2fixit]

I have a 50 gallon water heater and a 62 gallon bladder tank. The water from my well comes in SO cold (about 34 degrees) that only a trickle of cold water makes the shower comfortable. I suspect that when I change my bathtub faucets from 3 across knobs to a single dial control, i will need to put a ball valve in the plumbing access on the cold water supply to throttle back the cold water to as little as possible.

I dont know of a practical way around this, if your issue is caused by cold incoming water.

 

[Banjo Bud]

The pipe size theory would make sense if the problem always existed but it didn’t. It’s a new problem after my well pump was installed. The CSV is set to about 57 psi. I don’t know how I could measure the psi at the shower.

 

[Reach4]

What is the pressure while running the tub or shower cold before flushing that toilet? What is the pressure while that toilet is filling adding the additional usage?

The CSV is set to about 57 psi. I don’t know how I could measure the psi at the shower.

Measure the psi at the pressure gauge while the those things are happening. You could do this by

• running the loads, and running back to the gauge while the toilet is filling.
• having anther person call off the pressure gauge reading.
• taking a movie of the pressure gauge while you turn on tubs/shower and flush a toilet.

If the pump maintains 40 psi or more during the operations, repeat the test with a pressure gauge hooked to a laundry tap, an outside hose bibb, or the drain valve of the WH. This will let you measure the pressure after any cartridge filter or water treatment stuff.

 

[LLigetfa]

The CSV is set to about 57 psi.

Your shallow well pump might be way off the curve near deadhead pressure at 57 PSI so most likely you are not getting 7 GPM. Test to see how many GPM you are getting with a bucket and a timer.

A pressure gauge with a garden hose thread can be placed in one of several places to read the pressure if line losses are suspect.

I have a camera on my pressure gauge recording so I can review the operating pressure at any time.

 

[Valveman]

You can screw a test gauge to the drain faucet on the water heater. If the pressure to the water heater is less than the cold water side you may have a restriction in the line filling the heater.

 

[Banjo Bud]

Sounds like a purdy good idea. I’ll try that.

 

[Reach4]

It may go without saying, but to detect a restriction, you need to have water flow.

 

[Banjo Bud]

I will tell you that my HW tank is 13 years old. I drain a few gallons from it every month and have replaced the anode rod twice. So I maintain it well.

 

[Banjo Bud]

It may go without saying, but to detect a restriction, you need to have water flow.

true. So how do I find if the water flow into the tank is restricted? I thought maybe I’d turn the inlet valve off, then drain the tank, then time how long it takes to fill it. How do I calculate that? It’s a 40 gallon tank, there 1/2” copper inlet, the pump CSV is set to maintain 57 psi, and it supposedly outputs 7 GPM.

 

[Valveman]

I just cleaned my 50 gallon WH after 10 years, It got out about a 5 gallon bucket of white rock that you could tell built up and then broke off the electric heating elements. If the fill tube is coated with this material, the hot water will have less pressure than the cold water side. While running 3 GPM of hot water and 3 GPM of cold water at the same time, the flow and pressure should be the same on both lines. If the pressure in the WH is less than the water pressure gauge on the well tank, you most likely have a clogged WH inlet tube.

 

[Reach4]

true. So how do I find if the water flow into the tank is restricted? I thought maybe I’d turn the inlet valve off, then drain the tank, then time how long it takes to fill it. How do I calculate that? It’s a 40 gallon tank, there 1/2” copper inlet, the pump CSV is set to maintain 57 psi, and it supposedly outputs 7 GPM.

Put the pressure gauge on the WH drain line. Note the difference between the pressure on the pressure gauge at the tank and the pressure gauge on the WH. Then run hot water from the shower or tub. The difference will change from near zero to some amount, and that difference measures the restriction into the tank.

You can remote the pressure gauge on the WH by using a garden hose. That can let you have the two gauges in the same area, perhaps appearing in your movie. It is possible that your cellphone or camera can pick up the audio of you loudly calling out what water loads you are turning on and off. Or take notes, and compare the times.

Usually a 40 gallon tank would be fed with 3/4 inch pipe.

If the no-flow water pressure of the gauges differs, that is due to altitude difference and gauge calibration difference.

 

[Banjo Bud]

Put the pressure gauge on the WH drain line. Note the difference between the pressure on the pressure gauge at the tank and the pressure gauge on the WH. Then run hot water from the shower or tub. The difference will change from near zero to some amount, and that difference measures the restriction into the tank.

You can remote the pressure gauge on the WH by using a garden hose. That can let you have the two gauges in the same area, perhaps appearing in your movie. It is possible that your cellphone or camera can pick up the audio of you loudly calling out what water loads you are turning on and off. Or take notes, and compare the times.

Usually a 40 gallon tank would be fed with 3/4 inch pipe.

If the no-flow water pressure of the gauges differs, that is due to altitude difference and gauge calibration difference.

got it. I had to read it a few times but it makes sense.