Hot Water Heater Size / Expansion Tank Yes or No??

I am putting in a hot water heater in a week or two on a remodel I am doing. I have two bathrooms, one with a shower and bath, one with just a shower, and a kitchen with a dishwasher. Would a standard 50 Gal be sufficient or should I get a high recovery? It is myself, wife and two little boys.
Also, I have about 60 PSI of water coming into the house but about 120 PSI give or take, at the street. I have it regulated down. Do I need an expansion tank? Manufacturer was explaining to me that though it is regulated down before it comes into the house, the pressure at the street is still problematic and I need a expansion tank. Several people have mentioned to me that they don't think I need it. I am confused.
Finally, I have a 2500 square foot house and am debating whether to put a recirc pump in or not. I ran a return line for it just in case. I don't want to put undue stress on the pipes and our schedules are all different so a timer wouldn't even help. The first bath is probably 100-150 feet from the heater, the kitchen is above that bath and the next bath is maybe 100-150 feet from the kitchen.
BTW, I am leaning towards getting a Bradford White. Any other recommendations.
Any feedback on the above issues would be appreciated. Thanks.
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doing.
or
is
Anytime you use a pressure reducing valve you must install an expansion tank on the hot water piping. The reason is that a PRV will not allow the extra volume from expansion to back up into the street.

so
Small pump doesn't use much juice, you save on water, and your hot water capacity effective increases from the hot water piping volume. Let the pump run all the time.
MM
The first bath is probably 100-150 feet from

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some prv's allow for thermal expansion, such as the watts 25aub
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on the hot water piping.
double check your specs...tank goes on the cold side at the heater, otherwise i agree with you.
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snipped-for-privacy@earthlink.net (Michael Roback) writes:

50 gallon should be sufficient. You can always replace the elements with a higher wattage if you need high recovery, assuming the water heater circuit is ample.

Listen to the manufacturer. An expansion tank will prevent possible problems. They are neither expensive nor difficult to install.

Use top quality insulation on the pipes and use the recirc pump. Your other option is two water heaters located near the points of use, and you probably already considered that.
--
http://home.teleport.com/~larryc

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a higher wattage if you need high recovery
if he starts with 4500 and changes to 5500, the speed of recovery is hardly noticeable, and barely worthy of mentioning.
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If you have a backflow preventer at the street then you need a tank for expansion. It is not a definate but it is likely you will have problems if you don't. I put a backflow preventer on the cold inlet to the hot water tank, then install a small expansion tank between it and the hot water tank. This tank is made for the domestic side pressure/temp. Some codes require this.
Boilermate is best way to make hot water
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What Ned said, but: A lot of water utility's are now installing check valves on new and serviced meters for lawsuit protection, I recommend to all my customers that they install expansion tanks at their HWT just to be safe as they never know when the water co. my check and service their meter. Also if you check the cold side of the HWT for circ. reasons then you must have one between the check valve and tank. Dale

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