High water pressure; Moen cartridge

[Peabody]

I recently downsized into a condo, and sensing that the water pressure might be a bit high, today I bought a water pressure gauge from Home Despot, and got a reading of 90psi at an outside hose faucet. The condo was built in 1980, and I assume the pressure has been high ever since, although of course I don't know for sure.

I'm thinking about putting in a pressure regulator to bring it down to about 60psi, which would give me low-to-mid 50s at the second floor showers. Does anyone here have experience with these regulators? Is it possible that reducing the pressure after all these years might actually induce leaks? Are there any other downsides to these regulators?

I also need to replace a Moen 1200 cartridge that been there since 1980. I understand that getting the old one out after all this time can be quite an adventure, but what I haven't seen on Youtube is anyone using heat to help with that - a hair dryer, or even a propane torch. Seems like heat would help a lot. Has anyone here tried that?

[Ed Pawlowski]

Regulators are common and work well. I miss the 110# we had where I worked.. Curious why you want to reduce it after 40 years?

No idea about the cartridge.

[Peabody]

Well, when I Google the issue, and watch relevant Youtube videos, they all say that normal residential pressure is

40-60psi, and that maybe 70psi is acceptable, but that higher values put strain on the plumbing system and appliances connected to it, and that a pressure regulator should be used. But I just wondered if there's another side to this story.

It just seems the extra heat would expand the housing the cartridge fits into, and that would make it easier to remove.

[Marilyn Manson]

I can't imagine how lowering the pressure could induce a leak.

The pressure from my water authority reads at 90-95 psi at my cold water hose bibs.* I have a PRV set for about 55 PSI. Above 55 I tend to get some water hammer when quick closing valves like on the dishwasher and washing machine slam shut.

The common "wisdom" is that most household fixture aren't designed to handle high pressure over the long term. OTOH, I've had licensed plumbers tell me that that is a myth. In my case, I don't concern myself with that issue because for me it's more about eliminating the water hammer.

• When I moved in 35+ years ago, the cold water hose bib at the front of the house was (still is) plumbed before the PRV so that it is at full street pressure. However, the rear hose bib was after the PRV, therefore at the lower pressure. I tapped into the pipe to the front hose bib and provided street pressure to the rear hose bib also. SWMBO was quite happy since it cut her watering time in half. She loves her flower gardens.

I also added a hot water bib at the front. It's at the lower pressure of course, but it's nice to have hot water available at the hose bib.

A hair dryer sounds safe enough, a propane torch does not. I've never tried either. I've always been able to get the cartridges out using the various tools designed for that task. Granted, I've never had to deal with a Moen 1200. I know that some of the shower cartridges have heavy duty pullers designed specifically for them when the little plastic tool doesn't work.

I bought this the last I had to replace a 20 year old Moen shower cartridge. It worked perfectly.

I thought you needed to use a licensed plumber for all repairs?

[invalid unparseable]

I have had problems with old Moen cartridges and I see that there is a removal tool but I have not tried it:

My biggest concerns were removal from shower and tub where there are no shut off valves and I have to turn off whole house.

Last time around I saved the job for a plumber when I needed two other jobs done.

[Dean Hoffman]

I've used a torch many times over the years to help loosen plumbing. Outside, though. Heat a small portion of the outside fitting. It's easy to overheat things and expand both instead of just the outside one. Another trick is to put a bigger hammer on the backside of the fitting. Hit the fitting on the front side with a smaller one. The vibration shakes things loose. It also helps to alternate loosing and tightening of the fitting. I'd think that lowering pressure would decrease the chance of a leak.

[Marilyn Manson]

I've used that tool for my shower cartridge. Worked great. You just have to be patient and remove it very slowly. If you try to force it, you can break the cartridge into pieces. That would suck. My cartridge had been in for over 20 years and had been leaking for a while*, so there was considerable corrosion. The tool did it's job.

*Basement shower, leak wasn't evident until the sill plate of the wet wall got wet enough to eventually soak through the drywall. Fun repair...

I ended up cutting out the sill plate and bottom of the studs because they were soaked.

Over the years, every time I had to shut off the main valve to repair or replace a fixture, the first thing I did was install shutoffs so I wouldn't have to do that the next time.

The only time I've call a plumber was when the main valve itself needed to be replaced. Nope, not me. Wasn't going to touch it. Even he had trouble because of its age and location.

As Dirty Harry once said "A man's got to know his limitations."

[Peabody]

That's the rule. But I had pretty much talked myself into the idea that if no connection is broken or made, that would be ok for me to do. But even if I get a plumber to do it - since he will be installing the pressure regulator anyway - I think I would like to try the hair dryer for about 10 minutes before he attempts the removal, just to give us the best chance of success.

I checked with the City today about the pressure, and they said they would fix low pressure, but not high pressure. So it's my problem. And I think I will have the regulator installed if I can find a place for it. That's going to be the hard part - finding where the feed comes up out of the slab. I have no documentation of how that might have been done. I assume it wouldn't be legal to put it outside in the meter box, but I'll ask that question. That's really the best place for it if it would fit.

[Marilyn Manson]

Can't turn what water back on? The water to the fixture or the water for the whole house?

If that happened to me, only that single fixture would be out of commission because I have shut offs for every fixture.

I'm assuming you live in a warm climate. My meter is inside the house immediately (and I mean like 1 inch) after the main shut off which is just inside the block foundation. The water authority doesn't want to make it easy for a homeowner to tap into the system before the meter. Since they own the meter, we are not allowed to take it off and move it. My regulator is about

10' downstream from the meter. The only "branch connection" between the meter and the regulator is the pipe that feeds the hose bibs so that they are at street pressure.

Isn't there any place between where the service enters the building and the first fitting where the system begins to branch off to the various fixtures? All you need is about 6" of space.

[Peabody]

The water to the whole house. There's no shutoff between the shutoff for the whole house and the shower faucet. I wouldn't have built it that way, but it wasn't my decision.

And on the other side of the faucet is the standup tiled shower in the second bathrooom. So I can't even get to it from behind.

i have shutoffs for toilets, sinks, the water heater, the ice maker and the dishwasher. But not the shower faucet. or the outside hydrants.

Not particularly warm. We get below zero temps most winters. But pretty much all the houses are slab. No basements.

So the water comes into the house out of the slab. There's a shutoff valve there, but above that it immediately branches off three ways. So all of that would have to be re-done. And this is all inside an interior wall. It would not be cheap.

[Marilyn Manson]

Define "immediately". How much distance before or after the shut off.

If it's inside an interior wall, how do you know how it branches?

Can you post an image?

How is your meter in an outside box if temps get below zero?

[Peabody]

The shutoff body starts about an inch above the slab, What I can't see yet is what's above the shutoff. However, I can see two vertical pipes on either side of the shutoff going back down into the slab. So what I believe must be above the cutoff is a four-way equal cross fitting, with the fourth going up to the second floor. But I can't see that yet.

There's an opening where the shutoff handle sticks out of the wall.

I'm working on rigging up my 808 keyfob camera so I can stick it into the opening and take pictures. Film at 11.

The meter wells are about 18 inches deep, with cast iron covers. I've never understood why they don't freeze up if water isn't moving through them, but they don't. Maybe it's just that there's enough thermal conduction to the pipes that go straight down much deeper. We got through the big freeze of February, 2021, with no problem. Well, the water main broke, but none of the neighborhood meters did, or the lines coming into the houses.

[Marilyn Manson]

What's the frost line depth for your area? Just curious.

When my main shut off needed to be replaced, the water authority sent out a guy to turn the water off at the "street". (it's actually in my front lawn) The valve box (tube) was rusted shut so he couldn't get his 4'+ wrench down to the valve. I brought out a cup of coffee to warm him up as he worked on gaining access.

[Peabody]

I'm right on the 20" line.

Here the meters for all the slab homes are out at the street. I don't know about the older homes with basements. In my condo, there are about 10 meters in a raised island surrounded by concrete parking lot. And there's a shut off just downstream of the meter. I suspect that in my case the shutoff in the house is redundant. Anybody who wants to shut off their water does that at the meter.

No luck with the camera today. Will try again tomorrow if the covid booster this afternoon doesn't kill me.

[Marilyn Manson]

Seems strange to:

1 - Have above ground meters in an area that gets down to 0° (assuming °F) or even 0°C.

2: Have exposed shut-offs. Seems ripe for pranking.

I don't get why you suspect your shut off is redundant if your meter isn't out in the parking lot like the others. What other shut do you have that makes the inside one redundant?

[Peabody]

No, my meter IS out there with the others. So I have the shutoff in the meter well, and the master shutoff inside the house, with nothing between but a run of copper pipe. So either will shut off all the water to the house. What I don't have is a way to separately shut off the water to the shower.

One possibility, depending on what's behind the wall, is to replace the master shutoff with a pressure regulator. But I'm still trying to get pictures so I can tell what's in there. Do you suppose they make pressure regulators with a built-in shutoff? That might be the ideal, lowest cost solution for me.

I also need to investigate whether the PRV will prevent backflow. I don't want one that does that.

[Marilyn Manson]

[Peabody]

Yes, but the backflow occurs only when the pressure in the house exceeeds the city pressure by enough to allow the backflow to happen. If as in my case the city pressure is

90psi, and the regulator is set to 60psi, when the water heater heats up, the pressure can go back up above 90psi, which is worse than having no regulator.

Of course that's without an expansion tank installed, which I also don't have. I see all kinds of explanations of how they work, but none with any numbers. So lets say you have a two-gallon tank which is pressurized to 60psi when the water is cold, and the tank is all air at that point. If the water heating up causes the tank to become half filled with water, what is the pressure at that point? Is it

120psi because the air now occupies half the volume it did before? Well, it's just not clear to me what actually goes on inside these tanks, and what the resulting water pressure is.

Also, I think you have to depressurize the system to ckeck the expansion tank pressure. Otherwise, you don't know where the bladder is.

I think things work in this complex even with high pressure because the meters are still two-way - no anti-siphon valves or backflow preventers. So it's an open system.

[Marilyn Manson]

What goes on inside the tank - physically - is easily explainable.

As far as the "numbers" inside the tank, assuming that you have closed system (check valve at meter, perhaps) the pressure will basically be the same as the then-current system pressure.

But I'm not sure why you are concerned with those numbers. I trust what the tank manufactures tell me and use their tables to determine the correct size tank for the system in question.

e.g.

Checking the tank pre-charge is easy. AFAIC that's the only important number. Here's how to pre-charge and then check the pre-charge annually.

I recently installed a new water heater. With the pressure set at

60psi, my pressure would spike to 90+ psi after the heater fully recovered. I installed an expansion tank, pre-charged to 60psi. Now my pressure never goes above 75 and that's right after the WH fully recovers.

I'm fine with that since it only stays that way until any fixture is opened or a toilet is flushed. Worst case is the pressure is at

75 psi for a few hours. I'm not going to stress over that.

[Peabody]

Well, I'm not sure about that. I found this link that does go through the numbers.

The size of the expansion tank affects how much the pressure increases when the water is fully hot. But it's not going to be the same as normal system pressure. It will be higher that that, depending on the precharge pressure and the size of the expansion tank.

The thing is, in an open system with no regulator, an expansion tank provides no benefit. The pressure will always be at the City pressure. I think the regulator changes that, and I suspect requires an expansion tank.