Low hot water pressure

crebive · 04-25-2006, 08:51 PM

Hello all.

recently I have noticed our hot water pressure in our 12 year old house has been low. The cold side is fine. If I turn on two faucets in the house on the hot side then the pressure is very very low. Any thoughts or suggestions?

Thanks in advance!
D

Oldman · 04-25-2006, 09:49 PM

How's the pressure in the tub (Not the shower)?

Mike Swearingen · 04-26-2006, 12:50 AM

Usually, the hot water pressure is fairly equal to the cold water pressure going into the heater.
Has someone partially closed the water heater cold water supply valve? If it's wide open, the valve may be clogged with mineral buildup or debris. You can turn OFF the main water supply and dismantle the valve to check it.
And when is the last time that you flushed the tank?
Good luck!
Mike

crebive · 04-26-2006, 10:22 AM

I last flushed my water heater when I noticed the problem. The tub is the same as all the other faucets when on, it is low, when two faucets are on, very low.

I will look at the valve, hopefully that will be the only problem. How long do water heaters last? I hear they have a "mind" of their own and can last 2 years or 20.

D

Oldman · 04-26-2006, 07:25 PM

Sounds to me as if the valve has broke inside and is not opening fully (Had that happen before!) May need to replace the cut off valve to the water heater, on some gate valves you may could repair it.

redline · 04-26-2006, 09:05 PM

When you flush the water heater do you get good pressure from the hot water drain?

You may have sediment in the hot water tank or the sediment may be clogged in the line coming from the hot water tank.

Teetorbilt · 04-26-2006, 09:17 PM

The valve failing is a good one (sort of). I'm not a plumber and haven't seen one go bad in 30 yrs. BUT I've had 3 in the last 6 mos. Maybe the Chinese brass can't take our water.

Oldman · 04-27-2006, 06:40 PM

Teetorbilt, If they flushed the water heater I'd say they had to cut off the cold water into the tank, this would cause the seat to bottom out, but if the screw broke off it would not allow the washer to lift fully off the seat. If the cold water pressure is good the hot should also be good. Heck, it may be that it is a gate valve which requires many turns to fully open it.

MAS2006 · 04-27-2006, 10:01 PM

10 year avg on water heater before problems start, (leaking, etc.) Elects have a sacrifical rod in them. How hard is your water? Do you have 1/2 or 3/4 to and from heater and how far to sink or tub. 3/4 line will give better multi use preformance. Check faucet screen they display hard water build up first (around here clean once a year with out softner in system)

MAS2006 · 04-27-2006, 10:07 PM

:confused: What did you get out when you flushed it? What type of pipe do you have? Should be copper if only 12 yrs old.

crebive · 04-28-2006, 02:24 AM

haven't responded in a couple of days...sorry.

I tried the valve, but upon taking apart it seemed that the valve is one piece? I took the handle off, then a copper nut, but after that there was nothing more to take off. I had a threaded end sticking out of the valve body, with white plastic on the inside. The threaded end was where the handle is connected to and if the handle where on it, it would turn to open or close the valve. The plastic was solid and I didn't want to force anything. So anyway I put it all back together. I have copper pipe.

Funny, I consider myself a pretty handy guy. I completely gutted my master bath and put in new tile, new counters, new floor. Same for my other two bathrooms. Replaced my Kitchen floor, even finished my basement. But when it comes to plumbing I get intimidated to try anything. Water can cause so much damage, and I would hate to meddle with something and wake up in the morning only to find my basement flooded, because I failed to tighten a nut or something.

crazy....maybe time to call a plumber.

Thanks for all the advice
D

redline · 04-28-2006, 08:30 PM

Sounds like you have a ball valve.

Where is the next spot that you are able to turn and get hot water just after the hot water tank? Do you have a washing machine before any of the hot water faucets in the bathrooms or kitchens?

crebive · 04-30-2006, 05:03 PM

I do have a washing machine that would be the closest hot water valve

Okay so I drained my water heater again, and I got more green stuff and the water was a bit discolored. But still I have little pressure.

When I drain my hot water heater and i open the valve to drain it all the way open, should I get a pretty good water force out of that drain valve. the main water is off so there is no water coming into the house. When i was draining the water heater the water was running rather slow. My tank is 50 Gallons and it took FOREVER to drain.

Also, since I have copper pipe thru out the house, my problem should be either a valve to my water heater or my water heater itself, correct?

I just want to get to the bottom of this. My Heater is 12 years old, so maybe it is breaking down? My water in the house is still hot, just low pressure.

Our water is hard water too. we always get water stains on our shower doors etc. need to use CLR alot.

any other ideas or just suggestions, anything will help!
Thanks!
D

redline · 04-30-2006, 07:30 PM

Quote:

Originally Posted by crebive

I do have a washing machine that would be the closest hot water valve

Leave the main water supply on and disconnect the hose on the hot side going to the washing machine. See if the pressure drops at this point or if it is as high as the the pressure at the main coming into the house. If the pressure drops then the problem is from that point back to the hot water heater.

Okay so I drained my water heater again, and I got more green stuff and the water was a bit discolored. But still I have little pressure.

Leave the main water supply on when you drain the hot water tank. Does the pressure drop when you are draining the tank? If so then the problem is from the tank back to the main. It could be sediment in the bottom of the tank. You have hard water and the tank is 12 years old so it may be that the tank is near the end of its life.

If the pressure doesn't drop then the problem is as the water leaves the hot water tank or further down the line. The outlet from the hot water tank could be filled with sediment or corrosion. Do you have a di-electric fitting connection as the pipes leave the hot water tank?

When I drain my hot water heater and i open the valve to drain it all the way open, should I get a pretty good water force out of that drain valve. the main water is off so there is no water coming into the house. When i was draining the water heater the water was running rather slow. My tank is 50 Gallons and it took FOREVER to drain.

The water will drain slow if the main is turned off because there is not any pressure pushing the water out of the tank just gravity. If you drain the tank with the main water off then you have to open the relief valve near the top of the tank to allow air into the tank. You could also open a faucet to let air into the tank. Just be sure that you turn on the hot side of the faucet. If the relief valve is old then it may not close fully when you try to refill the tank.

Also, since I have copper pipe thru out the house, my problem should be either a valve to my water heater or my water heater itself, correct?
If you have copper thru out the house then that helps. Do you have copper coming into the house from the main? Do you know if the main line coming from the street is copper?

I just want to get to the bottom of this. My Heater is 12 years old, so maybe it is breaking down? My water in the house is still hot, just low pressure.

Do you have a coupling at the top of the water heater where the cold water comes in?
Or is it a solder joint?

Do you have a coupling connecting to the hot water coming out of the top of the tank?

If you have couplings for both the cold water coming in and the hot water coming out then I would disconnect the hot water pipe coming out fo the hot water heater and see if you have any blockage (sediment/corrosion) trapped in the pipe. If you have good pressure coiming into the hot water tank but you have a drop in the pressure as it leaves the tank then the problem is at the tank. If the pressure going into the tank is the same pressure that is coming out if the tank (at the drain and also at the first connection near the top of the tank then the problem is down further in the pipe. Process of elimination.

Our water is hard water too. we always get water stains on our shower doors etc. need to use CLR alot.
Are you on a public water supply or are you on a well?

any other ideas or just suggestions, anything will help!
Thanks!
D

Try these and see what happens.

crebive · 05-01-2006, 09:23 PM

Wow thanks for the detailed answers. When i leave the water to the tank on my pressure is good out of the drain valve. I'm not sure how to check for the water coming out of the water heater. I do know that the hot water to the washing machine is just as low as the rest of the house, as it takes forever for the machine to fill when we wash clothes in just hot water. So it sounds like it is the water heater? correct?
But let's say that the problem is farther down the line and I have a clog in the pipe somewhere and that pipe is located behind a wall, how would you fix that? Plus how would you determine where the clog is? I imageine there is lots of pipe behind the walls. Plus since I have copper pipe isn't that supposed to "resist" clogging?

Thanks again!
D

04-25-2006, 08:51 PM	#1
crebive Newbie Join Date: Apr 2006 Posts: 6	Low hot water pressure Hello all. recently I have noticed our hot water pressure in our 12 year old house has been low. The cold side is fine. If I turn on two faucets in the house on the hot side then the pressure is very very low. Any thoughts or suggestions? Thanks in advance! D

04-25-2006, 09:49 PM	#2
Oldman A Builder & Plumber Join Date: Apr 2006 Location: Farmville, VA Posts: 25	Low hot water pressure How's the pressure in the tub (Not the shower)?

04-26-2006, 12:50 AM	#3
Mike Swearingen Long-Time DIYer Join Date: Mar 2005 Location: On Albemarle Sound In Northeastern NC Posts: 1,460	Low hot water pressure Usually, the hot water pressure is fairly equal to the cold water pressure going into the heater. Has someone partially closed the water heater cold water supply valve? If it's wide open, the valve may be clogged with mineral buildup or debris. You can turn OFF the main water supply and dismantle the valve to check it. And when is the last time that you flushed the tank? Good luck! Mike

04-26-2006, 10:22 AM	#4
crebive Newbie Join Date: Apr 2006 Posts: 6	Low hot water pressure I last flushed my water heater when I noticed the problem. The tub is the same as all the other faucets when on, it is low, when two faucets are on, very low. I will look at the valve, hopefully that will be the only problem. How long do water heaters last? I hear they have a "mind" of their own and can last 2 years or 20. D

04-26-2006, 07:25 PM	#5
Oldman A Builder & Plumber Join Date: Apr 2006 Location: Farmville, VA Posts: 25	Low hot water pressure Sounds to me as if the valve has broke inside and is not opening fully (Had that happen before!) May need to replace the cut off valve to the water heater, on some gate valves you may could repair it.

Low hot water pressure