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hlat · Sep 18, 2009, 01:51 PM

Need advice in choosing new hot water heater to maximize hot water pressure. Plumber installed new intake/&out copper pipes, new coldwater cut off valve, new line to humidifer, correctly switched hot and cold lines to water heater, flushed - and still hot water pressure is low all over the house. We decided to get a new water heater in hopes of solving hot water pressure problem. Old water heater is 19 years old, 65 gallons, natural gas and was made by American. What should we look for - what to avoid - to maximize hot water pressure??
Plumber put in 6 elbows in hot water outlet to reach main pipe - would all these turns reduce pressure??

hkstroud · Sep 18, 2009, 02:03 PM

The only way a water heater can affect the water pressure is if there is so much sediment or mineral deposits in the bottom that the dip tube is clogged. Pressure coming out of the heater is determined by the pressure going into the heater. If you plumber went around replacing a bunch of pipe and valves without knowing something was defective, get a new plumber.

Was the water heater flushed? Should have been the first thing done.

See this post for my opinion about water heaters.

https://www.askmehelpdesk.com/plumbi...ns-394379.html

medic-dan · Sep 18, 2009, 02:03 PM

Water does not compress so if you have good cold water pressure you should have good hot water pressure unless there is something obstructing the flow. It sounds like you've gone through most of the system. You are suspecting a failure in the water heater.

Yes, elbows will reduce flow. So will corrosion in pipes, not usually a big problem if it's all copper. Is there any steel pipe anywhere in the system?

Make sure any valves leading to the hot water heater and each tap are fully open.

It shouldn't matter which brand water heater you put in. There are really only a couple of manufacturers out there.

There are tax credits for higher efficiency units, over 90%. Look for an Energy Star rated appliance.

Hope that helps.

massplumber2008 · Sep 18, 2009, 02:06 PM

Hi Hlat:

The choice of your water heater will NOT determine pressure in this situation, ;)

With what you have described, it sounds like there is no reason for the cold water supply into the heater to be the issue, so it may be reasonable to guess that the cold water inlet or the hot water outlet to the heater may have been damaged during instalation 19 years ago... maybe?

ANyway, purchase the new heater and be sure that the plumber does NOT apply heat to the inlet/outlet of the new water heater. In other words, all fittings that touch the new heater should be screwed fittings that get PRESOLDERED and cooled before applying to the threaded nipples of the new heater.

If water pressure is still low with the new piping, the new shutoff and the new water heater with nipples undamaged then you will need to start to look at shutoffs AFTER the water heater... may be that these are getting clogged.

Let me know if you want to discuss more...

MARK

hlat · Sep 18, 2009, 06:35 PM

Thanks, to all; this is my plan: Get a new water heater, replace the elbowed pipes with straight 3/4" copper, (now has 1/2" in/out take) cool any soldering before applying, only screw fittings will touch the tank, install full port ball cold water cut off valve, have plumber check pressure of cold water intake before final installation.

speedball1 · Sep 19, 2009, 05:01 AM

I'm amazed that someone hasn't asked what the incoming house pressure is?
That would have been my first question. My next question would have been,
" Do you flush your heater out on a regular maintenance schedual?" and if the answer was no I'd start checking the hot water inlet ports in the faucet cartridges. Ya-all are focusing on the heater end of things and overlooking the terminal end of the line.
Let's isolate the problem. Shut off the cold water to the heater and bleed off the pressure by opening a hot water faucet. Now go to the farthest fixture and disconnect the hot water angle stop under the vanity. Hold a bucket under the open pipe and have someone turn the watrer on to the heater. If you get a strong stream out of the open pipe the problem's clogged faucet cartridges, if the stream's weak then I would go back to the heater and check for heat trap nipples and go from there. But first I'd want to know how much pressure was entering the house.
There are a lot of questions unanswered here. Regards, Tom

hkstroud · Sep 19, 2009, 05:52 AM

Well, I would like to know if the plumber open a hot an cold valve to see if there was any significant difference in volume and pressure before he did his work. Maybe he did. If he did , did he check again after he did his work? Maybe he did, after he got his check.
Note that hlat says "correctly switched hot and cold lines". On a 19 year old water heater? It's been wrong for 19 years? Also note that lines are 1/2" hot and cold. Don't know how many taps.

massplumber2008 · Sep 19, 2009, 05:55 AM

Hi all:

I guess I assummed that the cold water pressure was fine or hlat would have asked about hot and cold water pressure... ;)

Seems to me that by all information given this issue is isolated to hot water only. Maybe Hlat will pop back and let us know more...

MARK

speedball1 · Sep 19, 2009, 06:22 AM

Mark,
You're probably correct but I've learned, over the years, not to "assume" anything.
When I go into a problem I like to enter with as much information as I can get.
If there's a hot water pressure problem then I'd like to know what pressure I'm starting with. Both going into the heater and coming out of it. If I have good pressure going in and lousy pressure coming out then I focus on the heater. If the pressure's good coming out I focus on the piping. If I can get good pressure out of the angle stops I go for the faucet cartridges. And that's the way I isolate a hot water pressure problem.
Hey! I'm open to criticisms and corrections on my method. If you-all have a better way I want to know about it. Regards to all, Tom