Pressure Booster on Hot Water

Patrick_North

<span style="font-size:12pt">We recently added a third floor bath. While water pressure is not problematic anywhere else in the house, the missus is not happy with the (admittedly) meek hot water pressure in the shower. There’s a dedicated (recirculating) ¾” supply to the bath. At some point, we’d like to add a water softener to the hot water supply and I’m sure this will only exacerbate the problem. </span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">I know that too high a water pressure can cause problems with wear and tear on appliances, etc. Is it feasible to add a booster pump to only the ¾” hot line serving the third floor bath? Any of the pumps I’ve looked at really seem to be “whole house” solutions- would that kind of overkill be ok assuming the pressure setting could be dialed back appropriately? Is there a better (smaller?) option for this kind of application?</span>

<span style="font-size:12pt"> It also looks like these types of pumps are not rated for hot water. If it is necessary to place the pump before the water heater, I’m imagining I’ll end up with more pressure than I need on the first floor to approach desired pressure on the third. Any thoughts on this? Worried about nothing?</span>

<span style="font-size:12pt">Thanks all,</span>

<span style="font-size:12pt">Patrick</span>

Steamhead

Is it the pressure

or the flow? Any restriction in the line, like a "stop-and-waste" valve, can cause reduced flow even if the pressure is adequate. 

Patrick_North

Maybe a little bit of both.

Hey Steamhead-

I am wishing I had put in a 3/4" mixing valve for the shower, but live and learn. Changing it out at this point would be possible but... Otherwise, I don't see any conspicuous sources of line restriction. The 3/4" lines serving the bath have full port shut offs in the basement, but that's all. The pressure at the sink in this bath is on the weak side, too, so I don't think it's anything in particular about the shower plumbing. Did that answer your question?

Thanks for asking,

Patrick

Steamhead

If the cold water pressure/flow is OK

then something is amiss in the hot-water piping, or maybe in the cold-water pipe going to the water heater. If the system is properly configured you should have about the same performance on both cold and hot. 

Patrick_North

Both weak

Both the hot and cold lines are on the weak side, but I only really care about the lack of pressure when it comes to the shower. The toilet fills just fine and there's ample pressure for hand washing. I was thinking about adding a pump to just the hot line as a way to focus my efforts, not wanting to add pressure to parts of the plumbing that didn't really need it.

But maybe I'm just overthinking the problem. I can't seem to find mention on the internet of others taking this approach, so it makes me wonder if it's not a good idea.

Thanks,

Patrick

Larry Weingarten

A rough rule of thumb...

... is that two feet of water height equals one pound of pressure per square inch.  (it's really more like .43 psi/foot)  If your floors are ten feet per story, that would mean the third floor has about five psi less than the second floor. I'd test static pressure with a gauge and see if that helps you to narrow down the problem.  A loss of five psi should be hard to notice.



Yours,  Larry

bob eck

Pressure Booster pump

take a look at installing a goulds pumps Aquaboost II constant pressure unit. It will do the whole house. This unit will give you constant pressure. Set the system for 50 - 65 PSI and the pump will only run if the system pressure goes below the system set pressure. The control on this system takes 230V 1PH and converts it to 120V 3PH and the pumps runs slow when you have only one faucet running and as you open (use) more faucets the pump runs faster automatically. grundfos also makes a pressure boosting pump for this type of job but it only boosts pressure it does not give you constant pressure. you could take the shower head off and use adapters to put a pressure gauge on it and see what pressure you are getting up there for both the cold and hot. when you came out of the shower faucet going to the shower head did you use 1/2" copper or did you use pex tubing?

Steamhead

Time to take some measurements

What is the system pressure, measured in the basement, when no water is being used at all?



How much does the pressure drop when you take a shower?

Patrick_North

Thanks, all!

Thanks for the responses everyone. Sounds like I've got some homework to do. Bob, the Aquaboost pump sounds ideal- i'll check that out. I'll report back after doing some additional investigating into my plumbing.

Thanks again,

Patrick

Abracadabra

what kind of pipes in the house and how old?

Iron or copper lines?







If iron, how old are the pipes?

I have 3/4" lines (copper) serving three baths on a stacked riser and the 3rd floor (35 feet up) has more than adequate water pressure for a shower. Incoming water pressure at the meter is between 45-50 psi.

Robert_25

What is the whole-house pressure?

How much water pressure do you have in the basement?



Any chance the screen in the shower head is clogged with debris?

rockhound57

test first!

Patrick, check your water pressure in the basement first! Are you on public supply or a well? If it's a well it's very easy to adjust the pressure, and there should be a guage on the system. Especially on older dug well systems, the press.switch would have been set at 20/40, which on the third floor, with 10' levels, would put you at 5-25 psi at the shower head, very weak!! Unless you've got very old copper or iron piping, I'd adjust the pressure up to 40/60.

 If you're on community or public water, check it at an outside faucet, most plumbers would have a test guage you could borrow, or you could get one or build one with parts from a hardware store. I would check all other options before resorting to the nuisance, noise, and waste of energy of adding a booster pump. If you know what it looks like, look for a pressure reducing valve near the meter,(or where the water enters the house). Again, if there is, it's easy to adjust, although if you haven't done it before, I'd ask your plumber to do it