Water pressure drop after boiler service?

Brad White_64

It is common after long-standing piping is disturbed to have loosened scale, minerals or other debris find their way to remote outlets and to clog small passages.

One way to check is to unscrew the aerator cap (screened fitting on a faucet where the water comes out). If you see small granules (or even bigger ones!) that could be a factor if not the cause.

Dishwashers also have small strainers upstream of their solenoid valves to protect those small passages, but plug the line in the process.

Other thing to check first- make sure all valves are fully open and if you have a tempering valve that it too is not clogged. In fact, if it is the hot water side of things, I would check this first come to think of it.

My $0.02

Brad

Marilyn_3

Water pressure drop after boiler service?

In the last few weeks, we've noticed a water pressure drop throughout the house, hot water is especially affected. We had the boiler serviced a few weeks ago -- could he have done something that affected the pressure? My dishwasher isn't cleaning the dishes on the upper rack; my upstairs shower is very low on pressure; and running straight hot water out of any faucet is slow going. Any suggestions?

Marilyn_3

tempering valve?

First, thanks much for the response! So, where is the tempering valve? We've never had a boiler before and many things seem mysterious. This one is only 4 years old. The boiler service call was a result of the parts of an old chimney falling into the exhaust pipe and causing black soot to spew out and cover the basement ceiling -- which is ok, since it is an unfinished fieldstone type, not too much damage to care about. The pipe was cleaned out and the chimney rebuilt. The boiler guy serviced the boiler after cleaning the debris from the pipe -- and it seems odd that it was just about then that we noticed the water pressure problem.

Someone suggested it could be a city water problem -- ??? We are higher than the houses around us and we were hooked up to city water 4 years ago -- when the new boiler was installed.

Marilyn_3

water heater?

Another question -- would adding a separate water heater help? There are only three of us living here and we usually don't run out of hot water. However, if it would increase the hot water pressure, it might be worth it. (And I have absolutely no idea what I'm talking about...)

LarryC

Clean and Flush

I am not a plumber or HVAC contractor, but my suggestion is to have a QUALIFIED person clean all of the screens and filters starting at the main shutoff valve and flush the water lines. Once the debris is out of the piping, then clean out the hot water tempering valve(s).

Good luck.

LarryC

Weezbo

We Love You ,Marilyn*~/:)


like it or not everyone has a struggle with grey areas in life.dont feel alone. you could have a variety of minor technicalities all preforming slightly off mark at cause. it may be the water pressure changes daily where you live,it may be a clogged water supply or faulty regulator a bit of debris in the anti scald devise or a poor heat exchanger,quality of water or possibly the piping arrangement was missing a piece right from the very start.

if you took a picture of the boiler and we saw a minor technicality someone would chirp up immediately often your choices as to "what can i do,Now?" increase when you have help to eliminate red herrings:) we have lots of them in this work and so we have become some of the best red herring fishermen in the world:)

having said that you could find someone who can determine whats what with some tools in their hands and you might be ahead of the game:)

things to do might be twist the anti scald devise higher and lower and back to a temp you like the water to be

call the utility company and find out if the muni has recently put in new fire hydrants or mains,

call a pro

send a picture of the boiler system:)

sometimes a valve may be inadvertently left closed while being checked during service those are some 'it might bes '.....,

Marilyn_3

I love this discussion board!

I do have a digital camera and I could take some pics of the boiler... I'll see what I can manage; it's kinda dark down there. I'll call the water department tomorrow though and start with them. Thanks for all your help.

Mitch_6

Poor pressure or poor flow

Did the teck that fixed your boiler have to turn the house water off for any reason. Typically a boiler service would not require house water to be shut off.

If the water was off did the teck turn it on all the way. It is not uncommon to crack a valve on to check for leaks but sometimes the teck gets distracted and forgets to turn it on the rest of the way.

Also can you run several devises hot and or cold at the same time. If pressure stays the same no mater how much is running it is most likely a street pressure issue unless you have a pressure regulator at your service. If as you open faucets hot and cold and pressure drops it is most likely a restriction.

Mitch S.

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Brad White_99

Tempering Valve

Ah, forgive me Marilyn-- I dived into the deep end of lexicon..

You seem to have a tankless coil or immersion coil within your boiler. All domestic hot water (that is, the hot water used for washing, bathing, laundry...) goes in as cold water to that heater then right out to the fixtures.

The temperature of that water can vary and at worst be too hot, there is a danger of scalding. So this is where a tempering valve comes in. (As Weezbo below notes, it is also called an "anti-scald" valve and you can see why.) It is a device with two pipe in and one pipe out. The two going in should be marked H for hot and C for cold. The "out" port is usually marked "Mix" or "Mixed" and is cast right into the valve.

The valve blends cold water into the hot water to give you a more constant hot water temperature to the fixtures, one we presume is a safe temperature. Thus your heater may generate 140 to 160 degree water (way too hot!) and the tempering valve knocks this down to, oh, say, 120F or so.

You are right, the chimney issue should not have anything to do with a pressure problem.

Could it be a city water problem? Sure, it could.

To test your water pressure you can go to a hardware store and for about $8 buy a hose-end gauge. Screws onto any hose-end valve and will tell you the water pressure at that point. An outdoor hose bibb will be fine if no other place. Typical pressures are between 50 psi and 100 psi, sometimes more. Most plumbing codes require a reducing valve to keep the water below 80 psi pressure, so ideally your pressure could be between 50 and 80 psi. Less than 40 would be of concern.

If you have 80 or so upstream of the hot water generating equipment, try taking a reading downstream, both while water is running. This will give you a "pressure drop" reading. If you are going in at say 60 (with flow) and leaving at say, less than 30, Houston, we have a problem... Normally 3-5 psi would be an acceptable drop, depending on flow rate.

Not to tag on to the other posts but I concur with suggestions to add an indirect or tank to the arrangement to give you something to draw against. Recharge it at leisure.

Marilyn_3

Thanks very much for all the info; you are so helpful! I will try to figure out how to measure the pressure if the city won't come out and do it for me.

I've been thinking for a while that a water heater is what I really need, although the problem with the pressure is a recent one, it's been an ocassional problem in the past, but not as severe as it is now.

I did check my water temp and it was set on 180 degrees. Isn't that too high? I reset it for 160 -- is that still too high?

It's always something...

Marilyn_3

Thanks! -- by a restriction, you mean a blockage somewhere, right? I'm calling the city tomorrow; will check with them first and then run through the excellent suggestions given here.

Brad White_99

Settings....

If you are talking boiler temperature, 160 to 180 should be fine. The higher will give you a higher temperature and/or allow a higher flow rate at a reduced temperature (they are all inter-related). If your domestic water temperature is set that high, yes, that would be too high, 120 is recommended, lower if children or elderly inhabitants.

But this raises another question, Marilyn- Ordinarily and depending on the type of boiler you have, you may want to consider controls that will boost the boiler temperature when domestic HW is needed and set it back when it is not. This is an appendix to "outdoor reset" whereby the temperature to heat your house is varied deliberately to correspond to outdoor temperature. Colder out? Use hotter water. Milder out? The temperature will automatically be reduced. Saves fuel and that saves money. But the domestic water has priority so will boost when it needs to. No need to keep the boiler at 180 degrees 24/7 you know!

This also undescores the desirability to install an indirect heater or at least a tank using the same heating coil you have now.

Not to saturate you with too much information but we all probably see lots of ways to save you money in the short and long term while improving your comfort.

As Weezbo suggests and as you concurred, yes, send photos- and ok... use a flash

Mitch_6

You may be

confusing your boiler aqua-stat with the tempering valve.

If you do not know for sure you should not touch.

Make sure to tap water is between 120 and 130 (code in Massachusetts) if you mess with it someone may get a burn.

Adjustments are best left to a pro.

Mitch S.

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Bill Nye_2

Marilyn

All of the above advice is good and sound, But... if you say it was ok before service and not ok directly after service was performed....... something must have happened.

If the boiler is in a confined space, or even if it is not, a valve handle may have accidentally been bumped.

Look to see if valves are fully open. If equipped with "ball valves" the handle must be parallel to the run of pipe, not perpindicular. The handles are easy to move and a vacuum hose or loose clothing could have caught the handle. Just another possibilitie

Marilyn_3

Water pressure drop -- boiler good for only 4-5 years?

So, I called the guy who serviced my boiler. He says that nothing he did could cause the pressure to drop and that I probably need a new coil. My boiler is just now 4 years old. Is that really as long can I can expect it to live?

Brad White_9

New coil?

Glad I saw the word "it" in, "Is that really as long can I can expect it to live?". We do not want to lose you this soon, Marilyn...

How long should a coil last? Depends on the hardness of your water. Some areas four years is as good as it gets, others last 15 or more... depends.

In the interim there are acid washes (done annually or semi-annually depending on hardness) which will postpone the replacement date.

Do you have a water softener? That should help also.

But the suddeness of the drop-off is what has me thinking something else. I do not know what, but if it is lime, calcium, iron, magnesium, the slow build-up is not a sudden event. Unless of course the "shock and awe" of hydronic surgery loosened up a kidney stone of sorts....

Leo

Maybe

Maybe the guy didn't do anything but I HOPE he came and looked at any valves he could of accidently hit and didn't condemn the coil over the phone.

Leo

Brad White_2

I am with you on the valve point, Leo

One of the last first things... happens way too often, does it not?

bob young

routine service call

another method would be to call a competent lic. plumber to solve the mystery.

Mellow_2

is the cold preasure low too. If it is lower than before look at the water coming in not the water heater.....