Here's my situation: Old line is clogged with deposits. House is about 100 feet from city shutoff. The house is 90 feet long with 4.5 baths, wet bar, dishwasher, washing machine, laundry tub, 2 outdoor spigots, 80 gallon water heater with recirculating pump and the hot water supply line from the water heater in the garage is about 85 feet long and runs through the attic. The hot water system also has a return line. Right now the house has TWO water service lines from the main in the street. We're obviously going to switch to one. Each line is 3/4" and I know to go to one big one I'll need a larger pipe. The city line from the main to the tree lawn will be 1 1/4". They only use 3/4" or 1 1/4". Here's the question: My plumber wants to downsize to 1" after the city shutoff all the way to the meter in the garage. I say go 1 1/4" the whole way from the shutoff to the meter instead of downsizing. What do you think? At the meter there are two lines(each 1 1/4") going into the wall. One goes to the main cold water supply line to the house and the other feeds the water heater. The city has three meter sizes available: 5/8, 3/4, 1" for residential. I say use the 1" meter but the plumber says 3/4". I don't understand that being that the feed to the meter will be 1 1/4" or 1". What would you say to both questions for service line size and meter size? BTW, there are three people living in the house and water bill runs about $65 per month so usage is on the large side. Thanks.

 

When in doubt, go large.

Everything is exposed now, very little difference in cost of pipe and meter set. I'd go with at least 1 1/4", maybe even larger (1 1/2") for the run to the meter then reduce to 1", given options of meter sizes.
Surprised city isn't looking at 1 1/2" meter set.

Your plumber needs to look at max demand on fixtures, with everything on, not what he thinks people use.

 

I agree that it is better to go larger than smaller, however, 1" is certainly sufficient to feed your whole house... And max usage should not be guaged on having all 4.5 baths, kitchen and bar being used at the same time as that will never happen... How many people live there? What will your usage be like? Your 80 gallon heater probably has a 1" inlet and should be fed with 1", but there is no reason to pay the extra money for the larger meter... and why do you have 2 meters? I believe you should go with 1" after the meter like your plumber suggests and go 1" to the heater from there also... And while it is always good to get a second opinion, your plumber's opinion should carry the most weight, since he is there to look at the situation.

 

There's three people in the house. We just have one meter. It's fed by two service lines each 3/4 in size. The house is a long ranch built on two lots originally. Two lines come in from the street and meet at the meter and turn into one pipe and go into the meter. After the meter you have one 1.25" pipe feeding into the wall for the house's water supply. I incorrectly described it above as two lines leaving the meter and going into the house. The 1.25" water line leaving the meter then goes to the attic and splits into two 1.25" lines, one feeding the 80 gallon water heater(used to be 2-40 gallon tanks side by side) and the other feeding a manifold setup that distributes cold water to various areas of the house. I even have a shutoff box with ten different valves for shutting off water to specific sections of the house and another valve that will actually drain the return line. I guess the plumbing system was designed by an engineer from PA back in 1949. It's like nothing I've ever seen. At the water heater the 1.25" comes out of the attic and goes into the circulating pump then downsizes to 3/4 going into the tank. The water leaving the heater goes through a 1" pipe which merges with the 1.25" hot water suppy line that runs the length of the house. Confusing enough? Would it hurt to go 1.25" for the feed to the house?

 

What kind of pipe do you have, and how do you know it is 1.25"? Anyway, you can certainly feed the whole house with 1.25" if you are not concerned about budget.... The pipe will be more expensive, the fittings will be even more expensive, and the valves on 1.25" are simply outrageously priced relative to 3/4" fittings... Most houses would get my just fine with 3/4", so 1" is certainly enough... 1.25" is just a waste in my opinion... Also, most 80 gallon heaters only have 1" inlets and outlets, so I would be surprised if you have 1.25" feeding it, but if you do, it is doing almost no good at all... Almost all, if not all, of your fixtures will have 1/2" or less inlets, most will be 3/8"... They just don't need all the overkill volume... I wouldn't be running 1.25" runs unless I was running over 200 ft. runs or more...

 

It's copper and the fittings and valves are all stamped 1.25". I've been around plumbing somewhat and I can confirm the size. the plumber and the city water department worker also identified it as 1.25".

You're right. The outlet on the water heater is a 1" pipe which goes into a reducer which is 1" on one side then 1.25" on the other side. The shutoff valve on the outlet is stamped 1.25". Then the main hot water supply pipe runs the length of the house and is 1.25". The water heater is fed by a 1.25" pipe which downsizes to 1" then goes into a B&G pump and then after the pump downsizes to 3/4 and goes into the water heater. There used to be two 40 gallon water heaters which split off after the pump.

The last fixture in the house is about 225 feet worth of pipe from the city shutoffs in the treelawn.

 

Didn't mean to doubt you but it is a common mistake... The runs in the house are all under 100', and I would still say 1" is plenty... The fixtures just don't use that much... Go 1.25" until you split off for the heater if it will make you feel better, but I assure you it is overkill... I worked at my Uncle's house today putting in a PRV valve, and he has 6 bathrooms, 3 bar sinks, kitchen sink, laundry room with a laundry sink, and two 40 gallon heaters... The service line is over sized because it runs over 700 feet from the street, but inside the house it is reduced to 3/4 immediately... 3/4" to the hot water heater, and 3/4" for cold... Then at each fixture it is reduced to 1/2"... He has no complaints with volume... Code doesn't even require 1", much less 1.25"...

 

Don't give it a second thought. I didn't take it negatively at all. I realize you needed to ask as my plumber also said people make that mistake pretty often. Thanks for all the info. It was really helpful. We've got a major problem in this city. They put in a 5 million dollar water treatment upgrade and it made matters worse somehow. The city is even offering to pay to do the city side of the service if you can show them a clogged up copper line when they dig it up. Otherwise it's $800. Galvanized services are excluded. It's hit thousands of homes throughout the city. Thanks again.

 

Ragnar mentioned that his Uncle's service line is over sized because of the 700' run from street. I'm going to be running a service line about the same length soon. What size should be run? Do you lose pressure/volume with water like you do electricity? Here in Alabama they put the meter by the road so if the meter outlet is too small should I run two meters or can I increase the size after the meter without affecting the press/volume significantly.