Water pressure regulator control adjustment:

This article describes exactly how to adjust a building water pressure reducer or water pressure regulator control, as part of diagnosing and correcting poor building water pressure or perhaps the need for a replacement water pressure regulator/pressure reducer.

Distinguishing between static water pressure, dynamic water pressure, and water flow rate can help diagnose water problems in a building. Here we explain these concepts and we describe how to measure water pressure and flow at a property where either municipal water supply or a private well and pump water supply is in use.

How to Adjust the Water Pressure Regulator on Municipal Water Supply

Find the pressure reducing valve or pressure regulator control for the building

A water pressure regulator or pressure reducing may be installed. See the illustration at the top of this page and at left. A device, usually a few inches across and often shaped a bit like a bell, may be found installed quite close to the building water meter.

The water meter is often installed where water pipes enter the building and the pressure regulator will be installed just after the water meter on the same pipe.

[Click to enlarge any image]

Notice the Pressure Reducing Valve Model

At WATER PRESSURE REDUCER / REGULATOR we explain that selecting the proper water pressure reducing valve (or water pressure regulating valve) is important to avoid both unsafe conditions (wire draw), and poor performance (water pressure too high or too low, noisy valve operation, etc).

Notice the Pressure Reducer Adjustment Screw & Lock Nut

You may see a set-screw secured by a lock-nut on the top of the pressure regulating valve or water pressure reducing valve that is built right into a water meter, or more often there is a separate device, shown in our photos, that includes a screw (and lock nut) or knob that will permit the water pressure regulator to be adjusted to set the water pressure up or down in the building.

Loosen the Lock Nut & Turn the Pressure Reducer Adjustment Screw

Which way to turn the water pressure regulator screw?

On most pressure regulators, after loosening the lock-nut around the adjusting screw,

• turning the screw in - or CLOCKWISE will raise or increase the pressure coming out of the valve. Watts® calls the valve output pressure the "reduced pressure"
• turning the screw out - COUNTER-CLOCKWISE will lower or decrease the output pressure from the valve

Watch out: Don't overdo-it. Just a turn or two should make a difference. Keep track of the number of turns so that you can go back to where you started if necessary.

Sometimes the municipal water supply may itself be temporarily shut down or running at reduced flow. Check with your local water department or neighbors.

Watch out: Increasing the building water pressure by adjusting the pressure regulator (or a pump pressure control switch) will not fix a poor water delivery rate from the source (municipal water main or local private water pump), but if the pressure was set too low to start with you may see an improvement by this adjustment.

If your loss of water pressure or flow was sudden, it's not likely to be a problem with the pressure regulator except in the less common cases of a blockage or failure in the regulator itself.

Watch out: don't set the water pressure reducing valve higher than necessary. Doing so wastes water and as we discuss

at WATER PRESSURE TOO HIGH: DANGERS, setting water pressure too high can cause both plumbing problems and actual serious safety hazards at buildings.

Water Pressure Reducing Valve Installation & Instruction Manuals

• Watts® SERIES 23B, 123LP, N250, N250B WATER PRESSURE REDUCING VALVE INSTALLATION INSTRUCTIONS [PDF], Watts® Corporation, 815 Chestnut Street, North Andover, MA, USA 01845-6098, web search 09/18/2010 Watts Regulator Corporation, 815 Chestnut Street, North Andover, MA, USA 01845-6098,
  
  Watts provides pressure and temperature relief valves, water pressure test gauges, water pressure regulators, backflow preventers, check valves, and other plumbing and heating controls and supplies.
  
  Website: http://www.watts.com/ Retrieved 2019/04/20 original source: http://bostonheatingsupply.com/Watts/Watts 23B, 123LP, N250, N250B Installation Instructions.pdf
• Watts® SERIES 223 SUPER CAPACITY WATER PRESSURE REGULATORS Product Data Sheet [PDF] Watts, Op. Cit., retrieved 2019/04/20 original source: http://www.wattsindustries.com/images1/7/PDF/ES-223.pdf
• Watts® SERIES 1146F, T156B and N256 FEED WATER PRESSURE REGULATORS INSTALLATION INSTRUCTIONS [PDF], Watts, Op. Cit. These regulators are used on hot water heating boilers and similar equipment NOT on building water supply systems
• Watts WATER PRESSURE REDUCING VALVES CATALOG [PDF] Op. Cit. retrieved 2019/04/20 original source: http://www.absgoc.com/download/real-state/ips-engineering/7. other-resources/valves/2. WATTS.pdf

If Adjusting the Water Pressure Regulating Valve Still Does Not Provide Enough Water Flow

If a small adjustment to the pressure reducing valve does not produce the desired water pressure and flow rate in the building, it's not a good idea to set the control to the extremes of its adjustment range. These devices work best operating near the middle of their rated pressure and flow ranges.

How to Get More Water Flow Through the Pressure Reducing Valve

As we explain

at WATER PRESSURE REDUCER / REGULATOR,

parallel pressure reducing valves/water pressure regulators can be installed, one set at a higher psi flow rate than the other. For example installing a Watts Model 223 pressure reducer set at 50 psi in parallel with a second Watts 223 pressure reducer set to 60 psi will allow increased total water flow capacity during periods of peak water demand.

Water Pressure Regulator Testing, Diagnosis, & Repair or Replacement

This article describes how to observe, diagnose, or perhaps how to test a water pressure regulator that seems to be misbehaving.

Some readers whose homes are connected to municipal or community water supply systems have commented that the water pressure in the home has been observed to increase to a pressure above the water pressure regulator set-pressure overnight when no one is using water.

First, what might cause water pressure to increase to abnormal levels in a building served by a community water supply?

At WATER PRESSURE VARIATION CAUSES we listed quite a few reasons that water pressure may vary in a building.

One of these is described as:

Variation in performance of the pressure regulator itself: a water pressure regulator may be misbehaving.

One water pressure regulator failure mode causes gradual increases in building water pressure above the set point on the regulator.

This may be due to an internal failure or leak in the water pressure regulator, dirt on the regulator valve seat, or a leak in an internal regulator valve or pressure-sensing diaphragm if your valve uses such a component.

A Watts 123LP low water pressure regulator is shown in our sketch at above left.

Notice that in the middle of the valve is a modular seat and disc assembly and at the bottom of the valve is the actual valve seat (above the "A").

If a piece of debris, (rust flake, dirt, mineral fragment) happens to jam on this valve seat, the valve may not close fully as it is intended to do at a given water pressure setting.

During the day when building occupants are frequently using water, even if the pressure regulator is feeding water at a pressure above the intended setting, no one may notice, because water use "bleeds off" the excess pressure.

But at night when no one is using water, a slow leak at the water regulator will feed more water into the building piping.

In an extreme case (which we OPINE would be unusual) combining a defective water pressure regulator and high municipal supply pressure (say over 80 psi i the water mains), the result could be leaky plumbing fittings, pipes, fixtures.

How to Test The Water Pressure Regulator

1. Read & record the initial static building water pressure using a pressure gauge.

By initial static building water pressure we mean the water pressure at the start of a test interval over which we're going to watch for a change in building water pressure.

When water is not being run in the building the water pressure should not change. If you observe water pressure just after plumbing fixtures have been run you will see the immediate pressure regulator response - it should restore water pressure to its set point. If, after that time no water is run in the building for some time period, say eight hours overnight, the water pressure should be the same.

Use a water pressure gauge that is already installed, or an add-on water pressure gauge that you can connect to a convenient fitting such as a hose bib or clothes washer hook-up.

See the gauge photo at the top

of WATER PRESSURE MEASUREMENT

If you have a water pressure gauge already installed (some homes include a water pressure gauge close to the pressure regulator even where the water supply is from a community supply) you may be reading water pressure on the gauge.

Watch out: as we explain

at WATER PRESSURE GAUGE ACCURACY,

pressure gauges may become inaccurate or sticky. Try tapping gently on the pressure gauge to see if its pressure reading changes.

2. Read & record the ending static building water pressure

At the end of a test period during which no one has run any water (we recommend over night if possible or eight hours), make a note of the water pressure again.

If ending static water pressure is lower than your start point we suspect that there is a leaky plumbing fixture, dripping faucet, or running toilet.

If ending static water pressure is higher than your start point we suspect that either:

• The pressure regulator has an internal leak, or
• The municipal water pressure in the water mains at the time of your start point was below the set point on your building's water pressure regulator

Water Pressure Regulator Repairs

Flush the regulator valve seat: you might be able to remove a bit of debris on the pressure regulator valve seat or in the valve assembly by loosening the lock nut and temporarily increasing the set pressure, followed by running water out at a nearby fixture.

Alternatively some water pressure feeder/regulators (usually lower-pressure devices found on heating boilers -

see details at WATER FEEDER Valves, Hydronic) include a bypass lever that can be lifted to temporarily bypass the pressure control and flush water through the valve.

Watch out: be sure to restore the set pressure to a safe level for the building.

Following pressure regulator valve flushing, you'll want to repeat the pressure test we described above.

If a gentle attempt to flush debris from the valve seat makes no difference and the regulator continues to overfeed water to the building, the pressure regulator needs to be replaced. This will require temporarily shutting off water at the main building water shutoff, draining water pressure from the building piping, then removing and replacing the pressure regulator device.

While it may be possible to disassemble and clean and replace water pressure regulator internal parts, unless homeowner repairs are specifically described in the installation and maintenance manual for your water pressure regulator, we do not recommend trying that.

It's rather easy to lose a tiny part or damage something, leaving yourself with no water in the building for still longer while someone dashes out for a replacement part.

A Guide to Building Water Pressure by Adjusting or Repairing the Water Pump Pressure Control Switch on a Private Pump and Well Water Supply

If your water pressure problems are concerned with a private well water supply system or a small community well water supply system (well, pump, water pressure tank, and pump pressure control switch) see the notes just below.

For details about diagnosing poor well water pressure and flow, start

at BAD WELL WATER PRESSURE or FLOW or go directly to the individual items listed just below.

• How to Adjust Water Pump Pressure: The detailed, step by step procedure for inspecting and adjusting the water pressure control switch is discussed in detail
  
  at ADJUST PUMP PRESSURE CONTROL.
• Diagnosing Water Pump Short Cycling on and off: If your water pump is clicking on and off too often or quite rapidly
  
  see SHORT CYCLING.
• Diagnosing Water Pressure Drops without explanation when the pump stops,
  
  see WATER PRESSURE FALLS SLOWLY, ERRATIC PUMP: bad pressure control switch, building water running or leak, bad pressure gauge, bad check valve, bad foot valve.
• Diagnosing & Repairing Lost Air in the Water Tank: The problem of lost air in the water pressure tank along with how to correct that condition are discussed beginning
  
  at SIGNS OF AIR LOSS.
• Diagnosing & Repairing a Water Pressure Control or Water Pump Control Switch: We discuss diagnosing and repairing a water pressure control switch that sticks "on" or "off" or simply won't operate,
  
  at WATER PUMP PRESSURE SWITCH REPAIRS

 

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2020-08-24 by Ray Radostits

water pressure drops from regulator set point and is real slow coming back to set point

On 2020-03-04 by Anonymous

Anon

If you have water elsewhere but just not in the kitchen I'd figure there's a valve closed somewhere.

On 2020-03-03 by Anonymous

@Groman Black,
gblack2050@att.net i put new hot water heater in now I don't have no pressure in kitchen

On 2020-03-03 by Groman Black

@Groman Black,

I put new hot water heater in now I don't have any water pressure in kitchen

On 2019-11-06 by Star

Thanks so much for your detailed reply, I will make my way over to the other page and continue this there if you don't mind :-)

On 2019-11-06 - by (mod) -

Star

I see a hydronic (hot water) heating boiler with at least 2 circulator pumps, and with what looks like asbestos lagging coating the boiler top and sides (if so, hazardous, do not disturb it).

You are right that a hydronic heating system should not be consuming water; there is a leak somewhere; often a small boiler leak seeps out on a hot component of the boiler, piping, or radiator/baseboard where the water evaporates; therefore you may not find a puddle or obvious leak point.

However there will in such cases always be a build-up of crud and corrosion and deposits of salts left behind as the water evaporates, so a careful and thorough inspection can find such leaks unless the leak is where piping or components are in an inaccessible area such as a wall or ceiling cavity.

While the manufacturers are careful to say that the pressure/reducer/regulator should not be used as an automatic water feeder, that's what almost everyone relies on in residential hot water heating systems.

Sometimes the regulator can be cleaned - there's a screen that clogs - to get it working again; most techs don't bother, they just replace it. Your system is, in a subtle way, unsafe if its water feed system isn't working since when no one is around the system loses water and can thus be damaged or could overheat.

Your comments are on a page for BUILDING water pressure regulators.

To read about the pressure-reducer / regulator used on hot water heating systems please see

PRESSURE REDUCING VALVE WATER FEEDER INSTALLATION

On 2019-11-06 by Star

Hey, excellent resource - thank you for all your hard work and long hours compiling it for our benefit!

[Click to enlarge any image]

We recently purchased a former commercial building that we are going to renovate and occupy as our home. It comes with a 1970's hot-water heating system with a boiler (see attached photo).

The makeup water valve has always been kept shut off, and the pressure in the 'closed' system drops by about 1lb every couple of days. The residential zone is two storeys (2 zones to this system) and I've been keeping the pressure between 15psi and 18psi to push against the 12' of head pressure to feed the upstairs radiators.

My questions:

does that sound correct so far?

And, regarding the pressure regulator just after the makeup water valve - I was told that it's "faulty" and won't control the temperature properly (hence the makeup water cannot be left turned on, I have to bring it up to 18psi and then shut it off again). Do you think if I adjust the pressure regulator that I might get it to do what it is supposed to?

There's obviously a small leak somewhere - and the system has been gone over thoroughly before we purchased looking for leaks (found none that they would admit to ;-) ).
Any input would be appreciated, thanks.

We'd like to be able to go away for a couple of months in the winter time but would have to hire someone to come in and tweak the pressure once a week or so as the system stands now.

On 2019-04-26 - by (mod) -

With the apology that of course there could be something else going on,

the most likely or common explanation of having to set the pressure regulator quite High just to get an acceptable flow rate

is that there is either of valve partly closed or there are pipes that are clogged in the system.

The clogged pipes would be a more suspect explanation if the hot water pressure was noticeably worse than cold because usually those hot water pipes clog first.

On 2019-04-26 by Coran D Oberlin

What would cause a water regulator hooked to Municipal Supply to require a very high setting such a 70 PSI just to get a relatively moderate flow rate?

...

Continue reading  at WATER PRESSURE REDUCER / REGULATOR - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

WATER PRESSURE REGULATOR ADJUSTMENT FAQs - questions & answers about adjusting water pressure, posted originally on this page.

Or see these

Water Pressure Diagnosis and Repair Articles

• AIR DISCHARGE at FAUCETS, FIXTURES
• CLOGGED SUPPLY PIPES, HOT WATER
• MUNICIPAL WATER PRESSURE DIAGNOSIS
• NO WATER PRESSURE
• PLUMBING LEAK DETECTION METHODS
• PLUMBING LEAK DETECTION & SHUTOFF DEVICES
• WATER FILTERS, HOME USE
• WATER PRESSURE BAD at SOME FIXTURES
• WATER PRESSURE FALLS BRIEFLY THEN STOPS
• WATER PRESSURE FALLS SLOWLY, ERRATIC PUMP
• WATER PRESSURE GAUGE
• WATER PRESSURE INTERMITTENT LOSS
• WATER PRESSURE LOSS DIAGNOSIS & REPAIR - home
• WATER PRESSURE MEASUREMENT
• WATER PRESSURE PROBLEM DIAGNOSIS TABLE
• WATER PRESSURE TABLE 1: PUMP WON'T RUN, WON'T STOP, or CYCLES
• WATER PRESSURE TABLE 2: PUMP RUNS, WEAK or NO WATER PRESSURE
• WATER PRESSURE TABLE 3: PUMP RUNS, NO WATER or INSUFFICIENT WATER
• WATER PRESSURE REDUCER / REGULATOR
• WATER PRESSURE REGULATOR ADJUSTMENT
• WATER PRESSURE REGULATOR BAD
• WATER PRESSURE VARIATION CAUSES
• WATER PRESSURE STOPS, RETURNS
• WATER PRESSURE TOO HIGH: DANGERS
• WATER PRESSURE VARIATION CAUSES
• WATER PUMP CAPACITIES TYPES RATES GPM
• WATER PUMP CONTROLS & SWITCHES - home
• WATER PUMP REPAIR GUIDE - home
• WATER PUMP INTERMITTENT CYCLING
• WATER PUMP PRIMING PROCEDURE
• WATER PUMP SHORT CYCLING
• WATER PUMP WON'T START
• WATER PUMP WON'T STOP RUNNING
• WATER QUANTITY TEST: WELL FLOW TEST
• WATER TANK: USES, TROUBLESHOOTING - home
• WELL WATER PRESSURE DIAGNOSIS - home
• WELL WATER PRESSURE IMPROVEMENT

Suggested citation for this web page

WATER PRESSURE REGULATOR ADJUSTMENT at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

INDEX to RELATED ARTICLES: ARTICLE INDEX to WATER SUPPLY, PUMPS TANKS WELLS

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