I have an old 2 story house on city water in an old part of town, with very very low water volume. The old iron pipe feeding the house is only 1/2 inch and is shared with the neighbors house which is vacant. The 100 year old city main is under a city street which is also a highway, so the cost to replace the main to the house is over $12,000.00. The city says their main is not scheduled for replacement in the near future, and since I am responsible for the line to their main, the cost of replacement is mine. Thus I am looking for an alternative solution. The main bathroom is on the second story (which barely makes it possible to use the shower), the half bath is in the basement and laundry is in the kitchen on the main floor. It takes forever to fill something like the washer or the tub. I have been looking at adding a Flotec pressuremate pump to the house along with some sort of water tank for storage of incoming water. I don't think a pressure tank alone will hold enough water to keep up with the use of multiple items, since the volume coming into the house is so low. My question is what type of storage tank is recommended and how many gallons for a 3 bed 1 1/2 bath house? Would this pump be sufficient with a large supply of incoming water, or would a pressure tank also be needed? Or, does someone have a better solution?

Wow, you have two really big problems. 1. 1/2 inch supply. 2. and most importanly, iron pipe(or lead) supply. Only real fix here is to replace supply. I know that's not what you wanted to hear, but. Adding a pump and pressure tank will help, but eventually the iron pipe will clog so much that no pump and tank will be able to produce enough volume to satisfy the house water demands. You would basically be throwing money into a temorary (if that) fix. Hate to be the bearer of bad news, but this is not going to be an easy or cheap fix.

Of course this is only my opinion, derived from years of plumbing experience. Hope the other folks here can give you advice that will help you, without digging up line. Take care,

Lee

I am really only looking for a temporary fix, since eventually the city will replace this main. If I can squeek by for 5 years or so, this street will get redone and then their main will get replaced, and I will get new connection to the curb stop. This will cut my installation price to only a couple thousand dollars...

I also forgot to mention that all plumbing in the house has been replaced with pex.

Okay. Your only option will be to add the pump and tank. The bigger the better( at least for the tank, in this case) Pump size really won't matter since you have no volume. Id say a half horse pump would be sufficient. The larger tank will hold more water creating better volume to the other pipes in the house. Pump alone will increase pressure, but when two or more fixtures are run at the same time, you will lose that pressure because volume is not adequate. Tank will help this until tank is drained then you are back to step one. This is why I would suggest a large tank. I may be off on the pump size, couldn't hurt to go three quarter or even one horse, but I feel it wouldn't really help in this instance.

So, do you think an incoming storage tank, say 200 gallons, then a pump and then a pressure tank? Or is a pressure tank necessary when using the flotec pressuremate?

This is the pump I am looking at.

Flotec PRESSUREMATE Home Pressure System - 1560 GPH, 3/4 HP, 1in. Model# FP4815

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Price: $339.99

In stock on January 5, 2009.
Order it now.
Ships from and sold by Northern Tool & Equipment.

Is there a better option??

I am not sure there will be enough volume for the pump without the water storage tank. Also not sure what kind of tank would be appropriate.

Im not familiar with the flotech, but I installed a grundfos on demand pump in my house. I have a lead service. I didn't want the cost of digging either. My pump doesn't require an external pressure tank, there is a very small one built into the pump. It works great for blowing my hair back in the shower, and gives great pressure to all fixtures in house(0nly one fixture). As soon as I turn another fixture on, my pressure drops because I don't have enough volume. Yes, a holding tank then pump, and or pump and pressure tank should help very much, but its a lot money to be spending for a temp fix. Have you talked to any local plumbers and picked their brains? I would bet they would say just put in a pump and pressure tank. Forget the holding tank. If pump and pressure tank don't solve issue, then move on to next step(holding tank).

If your pump is like the grundfos, then a holding tank, and pump would be sufficient. Shouldn't need press tank.

I will bet you that if you cut that 1/2" line in half, its probably got little more than 1/4" opening, if that. It's probably almost stopped up.

Your idea should work, until your pipe did like mine did two years ago, a piece of crud will break off and lodge itself in the pipe completely blocking flow.

And if your luck is like mine, it will be under the slab of the basement floor.

Be prepared to dig a new line in the near future no matter what you decide today.

You can install 50 gln storage tank in the attic, have incoming water go to the attic first before it goes to any fixture in your house. With this method you will utilize gravity to create pressure.

However, your 1/2" pipes are small. We usually all pressure to the system to compensate for undersized pipes. You may use Booster Pump to boost pressure to 75psi or so. It is not overly complicated and expensive to install this system. Of course, you have to be ready to compromise since adding pressure to small pipes has its drawbacks, too...

The name MTlandlord, makes me think Montana. If so, temps get to low and you would need to install storage(holding) tank in an area that is heated, to prevent freezing. If I'm wrong about your location, then milo has given you a good option. Andrew also gave you a pretty good idea of what is bound to happen sooner or later.