Water Leak & Hot water heater

[CarolinaGuy]

Need some help.

Here's the situation. I have a rental home about 90 miles from where I live.

Get a call from the tenant stating that they have a large water bill. The city says my house has used over 1000,000 gallons in the past two week. The basement where the plumbing and hot water heater is located is as dry as the top of your work desk. I spent all day troubleshooting this situation with the Public service director.

They are NO OBVIOUS LEAKS (ALL PEX) on the system yet the water meter is constantly running. I won't bore you with all the details but it the end of the day I finally isolated the leak.

If I CLOSE the valve supplying COLD water to the hot water heater, the meter at the street will finally quit running.

So the problem is isolated to the hot water side of the house, yet, again there is no obvious leak on the hot water or on any of the red PEX pipe supplying the 5 circuit on this line.

What do I do to fix this problem? Is the problem the hot water heater or a leak. How do I proceed.

Suggestions please.

CarolinaGuy

[jnaas2]

Where is the temperature and pressure pop off valve drained to. I have seen them go bad and run a solid stream of water

[HayZee518]

looks like the TP vavle isn't opening - he said the cellar is dry as a bone. I had a similar experience in a trailer. the hot water line to a bathroom faucet inside a wall was leaking but with no obvious puddle underneath. it was all absorbed by the insulation. eventually it made its presence known. open the breaker to the hot water tank. close the hot water outlet and watch your meter. if it spins leak's in the cold water supply. look for an outside valve [garden] leaking. go through the process of elimination to find the leak - use a systematic approach.

[CarolinaGuy]

Thanks for the response.

The entire system has been checked and double checked, there are no visible leaks in the system

The cold water side checks (shutting down portions of the system) had no affect on the meter running at the street.


When I turned off the cold water supply to the hot water heater the meter at the street quit running.

This indicates to me that the problem is in the hot water side of the system. From the hot water heater to the 5 faucets on the hot water side.

To date the City water department says overs 150,000 gallons has gone through this meter. Where is this volume of water going. The lines are over head in a full basement with dirt floors. The floors are dry dusty sand. Where is the Water.

The Public Services Director suggests that the water heater may have a pinhole leak inside. The area around the heater is dry, no leaks. Where is the water.

I totally perplexed over this problems. This is rural NC, very few plumbers, no training, only one in town and I'm about to believe I know more than they do and I don't consider myself a plumber.

[HayZee518]

well, the water meter operates off a rotating vane inside it. no flow should stay at zero, needle movement is proportional to flow. if there are no obvious leaks at each faucet, and you say you have five lines manifolded off the main, try shutting down each branch off the manifold. this will isolate the leak in a certain branch. water may be leaking inside of a wall where you can't see it.

[LazyPup]

The city is saying that 150,000gal of water have gone through the meter.

Water occupies 7.5gal/cu.ft thus the amount of water in question is 150,000gal/7.5gal= 20,000cu.ft.

That would be enough water to fill a 50'x50' basement 8ft deep yet the post says the basement has a dirt floor and that is dry. I think we can rule out any possibility of a leak in the walls or ceilings.

The post states that the flow stopped when they turned off the cold water supply to the water heater.

I would suggest you begin by turning off going throughout the structure and make sure all hot water faucets and valves are turned off then turn off all the valves on the hot water manifold When that is done turn the water heater cold water supply valve on and check the meter. If you note flow at the meter turn the water heater cold water supply valve off again to confirm the flow stops.

If you had flow with the manifold valves closed and the water heater supply valve open the problem has to be between the water heater supply valve and the manifold.

Normally the only active component in that area would be the water heater T&P valve, which can easily be checked by tracing the T&P valve discharge line to its point of termination and physically looking to see if there is water flow.

There is one other possibility that is so rarely used that most homeowners are not even aware of it.

The Plumbing code requires that a water heater T&P valve must terminate by gravity flow outdoors or into an approved "indirect waste receptor".

When a water heater is installed in a basement where the T&P would be below grade it cannot terminate outdoors by gravity flow. In a situation where the sewer line enters the basement at a point higher than the discharge level of the T&P valve gravity flow to an approved indirect waste receptor cannot be achieved. In this situation the code requires electric water heaters to be installed on or above the ground floor where gravity flow can be achieved however we may still install a gas water heater in the basement by removing the T&P valve and replacing it with a WATTS-210 GAS shutoff valve.

The gas supply line is then plumbed into the Watts-210 shutoff valve and then from the watts valve to the water heater gas control. The Watts valve has a sensor similar to the T&P that will close the gas supply if the pressure in the tank exceeds 150psi or if the temperature exceeds 210degF.

When we install a WATTS-210 shutoff valve we are required to install a Pressure Relief valve at a high point in the potable water distribution system, which would typically be in the attic space, then a discharge line from the pressure relief valve is run outside in the same manner as a T&P valve discharge line would be.

I mention this because this is an older home with a dirt floor basement so I doubt that is has floor drains, therefore it is very likely they may have a watts-210 valve on the gas line and the water leak in question is originating from a malfunctioning pressure relief valve in the attic space.

[CarolinaGuy]

Again thanks for the suggestions & recommendations. I will give a progress report about this time tomorrow night.

CarolinaGuy

[rickwhoo]

do you hear water running?