I recently (several months ago) installed a LET2 expansion tank onto my water heater line...(replaced one, to be more accurate).

However, my house does not have a water pressure gauge (so I did not know exactly what my water PSI was/is).

I installed the expansion tank (but did not adjust the pre-charged 38 PSI value of the expansion tank itself).

What issues may I face here?? Will I have problems if my expansion tank PSI chrage...is not set exactly to the same PSI charge of my incoming water?

Thanks

yes you will have problems since normal water pressure is 60psi. this means that the tank cant do its job. the tank should have been charged to what ever your incoming water pressure is.

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PLUMBERS "Protecting The Health Of The Nation"

Ok - Thanks -

So is my best option....To

1. Turn Off my main water supply (or supply to water heater line).

2. Run hot water lines in house (to drain water from tank).

3. Can I then use like a bicycle pump to increase my expansion tank pressure to say around 55 PSI...

4. Then turn back on my main water supply line?

5. (DO I need to shut off my hot water tank?? Turn it off? prior to all this?)

Thank you


Also, what type of issues may I have??



Edited 1 times.

When your water pressure matches the pre-charge tank pressure, you are getting the maximum capacity from your expansion tank. If not adjusted, the tank is still working, just not to full capacity.

First, measure what your water pressure really is. You can find $10 pressure gauges that connect to a hose bib at just about any hardware store. They should be accurate enough.

Turn off the water supply and open a nearby fixture to relieve the water pressure.

Read the manufacturers specs for your tank to make sure you DON'T GO ABOVE THEIR MAXIMUM LIMITS.

Using a compressor (a hand pump and air pressure gauge will work also) adjust the tank pre-charge air pressure to match your incoming water pressure.

Turn on the water supply and enjoy.

No, as soon as you turn on the water the air in the tank is compressed to the actual system pressure. All that happens if the initial charge is too low is that more water enters the tank and the amount of air is smaller, but since the actual amount of expansion is about a cup or less, almost any amount of air will compensate for it.

good call hj, ive never adjusted pressure on an expansion tank.

Hmmm, I'd better contact the manufacturer of my expansion tank and tell them their installation instuctions are useless.

lefty75, so you have never followed the installation instructions then huh?

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PLUMBERS "Protecting The Health Of The Nation"

"Pre-Installation
1. Remove plastic cap from air valve.
2. Adjust pre-charge to equal incoming pressure.
3. Replace and tighten plastic cap on air valve.

Warning:RUPTURE OR EXPLOSION HAZARD A relief valve must be
installed to prevent pressure in excess of local code
requirement or maximum working pressure designated in the Product Manual,
whichever is less. Do not expose Product to freezing temperatures or temperatures
in excess of 200° F. Do not adjust the pre-charge or re-pressure this Product except
for any adjustments required at the time of initial installation, especially if Product
corroded, damaged or with diminished integrity. Adjustments to pre-charge must be
done at ambient temperature only. Failure to properly size the Product or follow
these instructions may result in excessive strain on the system lead to Product
failure, serious or fatal personal injury, leakage and/or property damage."
[www.amtrol.com]

If the precharge is too high the tank will not absorb the expansion until the pressure exceeds the precharge pressure.

If the precharge pressure is too low the tank may be excessivly full of water even before the thermal expansion takes place which may limit room for expansion, add additional weight to the tank, and, or, stress the tank bladder. These factors may reduce its service life.

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Edited 1 times.

Nor have I, as long as the initial pressure is below the system pressure.

if the bladder isnt set to the incoming pressure you shorten the life of the tank.

so it does matter what the tank is charged to

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PLUMBERS "Protecting The Health Of The Nation"