Durring renovations of my home eight years ago, my contractor
installed a water backflow prevention valve on my water heater. I
think he told me it was required by code at the time, so I didn't
think anything of it. All these years later, my wife and I keep
trying to find a shower head that gives us enough pressure to take
good showers with the reduced hot water pressure that is caused by
this backflow preventer valve. We are tired of it. After reading
that it is typically required by cities to prevent water from flowing
back into the main water supply of a city after entering your house, I
question it's necessity since I live in the country and get my water
from a well. My water pressure setting on my well is 50 -80psi (cut
in/ cut out). I also am experiencing frequent releases of hot water
our of the pressure relief fitting on the tank, which is directed
outside. I read that the backflow preventer could be causing this and
isn't a desireable thing.
So, my question is if it would be considered okay to simply remove the
backflow preventer valve from my water heater, thus eliminating the
high pressure releases from my water heater pressure relief valve, and
also allowing full well tank pressure through the water heater tank
and out my shower head? Thanks for any help.
As you state, they are required by code on the city water system. I have no
idea what your local codes are. They are also used on sprinkler systems to
prevent sucking in lawn chemicals in the event of a pressure loss.
I theory, the backflow device is protecting your system in the same manner
as the city system. Personally, I'd take it out if it was a problem. I
don't know anyone that has ever heard of a contamination problem caused by
At work, we have one on our main water line coming into the building, but
they still make us have on on boiler feeds since they are pressurized.
If the tank is releasing water, it should have an expansion tank in the line
to prevent this. It is either missing or not working. As the cold watr
heats up, it expands and has to go somewhere. If you have a backflow valve
inline, the water can not go anywhere as it expands and builds presure so it
goes out the relief valve.
As an adult, I've lived in two places with pump water and one with
city water, all in Florida. Never had a backflow preventer anywhere in
any of the systems. I suppose the idea is that heating the water might
increase the pressure enough to push it back into the water main.
Would have to push a lot of water in most cases, and would not apply
at all to an isolated, single-family system.
My sister's house (used to be our parents' house when they were alive)
has a backflow preventer at the street, and it requires annual
inspection. The reason is that there is also a pump on the property,
which for nearly 50 years was the water supply for the house. The pump
now only supplies the water-modulated heat exchanger for the heat
pump. That system is completely isolated from the city water system.
However, it seems a reasonable precaution to require the backflow
preventer in that situation.
As I understand it a backflow preventer valve prevents water from flowing
back towards its source, but it should not prevent flow in the direction of
the user. Either the valve is plugged up from frequent use (and minerals),
or the showerhead has a flow restrictor or 2 preventing full flow to the
showerhead. I would look first for flow restrictors in the showerhead and
faucet valves to it, then (if that isn't enough) to replacing the backflow
A good backflow preventer should not reduce the pressure. I have a
3/4 one on my sprinkler system and I have branches with 3 and 4
sprinkler heads on them. If it is too small it could be a flow
restriction and that may be what you are experiencing. A larger
diameter one should solve that. As others have poited out any sort of
check valve on the water supply to the hw heater should also include
an expansion tank. Some code may require it even on a well. The
problems started showing up with efforts to reduce energy usage.
People turned down their hw temp and there is stuff that will grow in
hw if it's not too hot. Pressure drop on the cold side can draw water
out of the hw tank in reverse and you end up drinking it. It's really
not much of an issue for the other water customers as it's about
impossible to end up with a backflow situation that is so bad that
water from a hw tank ends up all the way back out in the street. But
that is often cited as the reason for the code anyway.
check for clogged shower head, remove flow restrictor, and my favorite
if you have a sprayer on a hose replace the entire assembly.
the hoses interior sometimes detoriates and flow will be obstructed.
symptom great initial flow but quickly drops.
its a realtive of bad brake hoses causing the caiper to stick on
burning out shoes and rotors.
the rubber inside line acts like a check valve....
i had both the shower low flow, and stuck caliper in same week. at
least found both in same week, the problems had been going on
its not a bad idea to cycle all valves close and open a couple times
with shower full on and showerhead removed in case dirt is clogging a
you could also have a bad shower control valve espically the temp
they can cause low flow
If it is restricting the flow, it must be really gunged up, and not
functioning anyway. I'd put the next size larger in there to insure flow,
sweat the larger reducing couplings on there, to get down to the original
sized line, and then SharkBite the whole new assembly into the old line. A
one way is not a bad idea, and would prevent major disaster if the water
ever did go backwards for any reason, and had gunge in it, and if it is
code, it would at least be done right, although, who's going to check it?
Heart surgery pending?
Read up and prepare.
Learn how to care for a friend.
Might be interesting to install a decent pressure gage on the shower
outlet to establish the true operating water pressure. A reading close
to the well settings would indicate that supply lines to the shower
are adequate and that the problem then is lack of an expansion tank.
After installing one, the readings will be much more uniform.
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