Whole house water filter increased back pressure?

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Ledvedder

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Hi everyone! I'm new to this forum. I'm a basic DIYer, by no means a professional. I ran new 3/4 copper pipe to install a whole house water filter. I installed shut off valves and pressure gauges before and after the filter system, as well as a straight bypass with a shut off valve. I've noticed that when my hot water heater runs, the pressure increases on the outlet side of the filter (80-100 psi), but remains consistent at the incoming side (60 psi). When the pressure is increasing, if I open the bypass valve up top, the pressure drops to the same as the incoming side (60 psi). I've also noticed the relief pipe on my hot water heater has started dripping. It has never dripped before. Any thoughts would be greatly appreciated! 20230106_152559.jpg
 

RS

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Apparently the new filter has a check valve built into it, I have installed a few filters, but never one like that. You either need to disable the check or install an expansion tank between the filter and the water heater.
 

wpns

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I wonder if it's possible to disable the check valve?
RS got it in one. Never heard of a cartridge filter with a check valve before, but there’s a first time for everything.

You might be able to remove the check valve, but you probably want to determine what it’s for first. Check the manual or ask the manufacturer.
 

wpns

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So it turns off the water for you when you change the filter? Not sure I’d try to “fix” that one, either add a reverse check valve, an expansion tank, or a normal filter housing. Do those cartridges do anything special? I’ve always used Pentek 10 with r50-bb sediment cartridges, but my water is fine.
 

Ledvedder

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So it turns off the water for you when you change the filter? Not sure I’d try to “fix” that one, either add a reverse check valve, an expansion tank, or a normal filter housing. Do those cartridges do anything special? I’ve always used Pentek 10 with r50-bb sediment cartridges, but my water is fine.
It does, but I installed stop valves on both sides of the filter, as well as a bypass valve, for when I need to change the filter or do any maintenance on it. I don't see how a reverse check valve would help, since the filter is stopping the back flow when the hot water heater runs.
 

Twowaxhack

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You can do a thermal expansion tank or get a pressure relief valve made for relieving thermal expansion, there are various types. Or like someone else said, remove the check valve if possible.
 

RS

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Another thing about your filter, does it have a transparent housing? If so, is it exposed to any sunlight? I was told never to use a transparent filter housing if any sunlight is present, it will increase the possibility of bacteria growing in the filter. I don't change filters by looks, I change them when the flowrate decreases. If you can determine where the check valve is in the filter you could drill a small hole through it. I have done that to the check valve in a submersible water pump for a special situation.
 

Ledvedder

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You can do a thermal expansion tank or get a pressure relief valve made for relieving thermal expansion, there are various types. Or like someone else said, remove the check valve if possible.
My hot water heater has a thermal expansion valve rated at 150psi. I definitely don't want the pressure getting that high.
Another thing about your filter, does it have a transparent housing? If so, is it exposed to any sunlight? I was told never to use a transparent filter housing if any sunlight is present, it will increase the possibility of bacteria growing in the filter. I don't change filters by looks, I change them when the flowrate decreases. If you can determine where the check valve is in the filter you could drill a small hole through it. I have done that to the check valve in a submersible water pump for a special situation.
It's not exposed to sunlight.
 

Ledvedder

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I just purchased an expansion tank. I figured I might as well do it right the first time. My only question is, can the expansion tank get installed horizontally? Or only vertically?
 

Twowaxhack

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I just purchased an expansion tank. I figured I might as well do it right the first time. My only question is, can the expansion tank get installed horizontally? Or only vertically?
Any way you want, just make sure it’s supported. They can get heavy when they’re in operation or fail and fill with water.

The 2gal tank weighs about 17-18 pounds when it fails.
 

Ledvedder

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Do I have to completely empty the hot water heater to install the expansion tank, or just release the pressure with the relief valve? I'm seeing conflicting installation methods.
 

Twowaxhack

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Measure your maximum static water pressure.

Pick the expansion tank size you need using the guide provided by manufacturer.

Inflate expansion tank with air to match your maximum static water pressure.

Turn water off and relieve water pressure

Install expansion tank

Turn water back on

Check for leaks

Check that thermal expansion is now controlled

That’s all there is to it
 

Ledvedder

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Can anyone think of a reason why I can't slip this ball valve onto this pipe? 20230109_133009.jpg 20230109_133003.jpg
 

Twowaxhack

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Probably because it has a pressed joint above it and that deforms the pipe.

There’s also an oring in the fitting above where you cut. Don’t burn it up with a torch
 

Ledvedder

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I ended up using a shark bite valve. It's not the cleanest job ever, but it works. 20230109_151436_copy_3000x4000.jpg
 

Ledvedder

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Ok, I'm noticing that the pressure isn't going up as high as it was before, but it is going about 15-20 psi higher when the hot water heater is running. Could this be caused by the expansion tank not being charged enough, or too much?
 
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