Almost any locksmith should be able to re-key these alike. It may require changing keyways or cylinders if they don't use the same blank. Take the cylinders/keyways to the locksmith - that way you don't pay for travel time.

Another option is the kwick-set smart locks.
They are slightly more, but you can change the key, at will.

Don't buy Weiser.

What has to happen is this: somewhere along the line you will have to have the same key cylinder in each lock. One problem with cheap production locks like Kwikset is you will have difficulty finding cylinders with the Kwikset key way and configured to work in a Schlage lock set, or a key way that will fit another manufacturer's key and will fit in the Kwikset lock set. Clear as mud, eh?

The Kwikset uses different length pins than Schlage, so that complicates things just a little. Weiser is not the lock it never was any more.

So, a locksmith will straighten you up lickety split. They have an awesome selection of lock (key) cylinders and can swap things around like magic. Kwikset is anti-magic, though. They may try to sell you replacements for some lock sets and they'd not be trying to scam you.

HOWEVER, almost all commercial and high quality homeowner grade lock sets and cylinders are, essentially, fully swap-able. That means you can use any key/cylinder in almost any lock set*. That lets you key your house to match any key you already have, such as your office key, and cut down on the metal clanging on your keyring. You can also buy decent brass (not that laminated Master junk) padlocks and key them right into your home entry door system.

Did I mention that I think Kwikset is junk*? Thin cheap pressed powdered pot metal junk? No?

*very broad statements; your mileage will definitely vary.

When we moved to our current home, I got a security company to install Medeco 1" deadbolt locks in all the doors. Wasn't cheap, but they have been trouble free for 20 years. It's great having just one key on your keychain.

Thanks everyone.

I should have clarified I don't want to keep any of the old keys.

So the original plan seems still appropriate. Fully replace the knob/locksets on the back and garage (Weiser and Quickset) and take out the cylinder from the front (Gatehouse) and have a locksmith turn all three (2 new Schlages and one existing Gatehouse/Schlage cylinder) into the same new key.

Yes AndreiD that is exactly what I would do unless you wanted to replace the Gatehouse/Schlage lockset then you buy three new ones all KA from the factory.

If you can find the brand/type of locksets you want at one of the big box stores, they will have the key number printed on the side of the box. In most cases you can find two or three locksets on the shelf that match and use the same key. Then all you need to do is get the existing Gatehouse lock keyed to match the new locks. If you remove it and take it to the locksmith for the rekeying it should be a fairly cheap job.

Bruce

I dislike Weiser and have never had good luck with them. I acquired them when I bought houses that already had them. The latest was about 12 years ago and the locks were apparently the better line of Weiser. They looked good, worked just so-so. For additions to the house, I used Kwikset. In this rural area, more expensive locks do not slow brutal force burglars at all. I discovered that the most recent Weiser Locks readily accept the Kwikset key blank. But to make a usable key for the Weiser using the Kwikset blank requires shimming one or the other (I cannot remember which) in the duplicating machine-- the locksmith knew all about it. With a Kwikset key that would operate the existing Weiser locks, I used my pin kit to make the new additional Kwikset locks work with that key.
Rekeying Weiser locks is not so easy. Kwikset is easy for me to do.
Not everyone will like this solution, but it was the low cost option for me.

I replaced the outside doors with steel insulated doors and steel door jams - fastened way into the studs. This plus the Medeco deadbolts makes for a real secure set up.

Schlage are the better option for exterior doors and they are designed extremely well. The best thing about Schlage locks is, if you locked yourself from inside, you can still open the door and leave, which is not available in Quickset.

Huh? What in hell are you talking about her "if you locked yourself from inside, you can still open the door and leave, which is not available in Quickset."? And being a locksmith you should know how to spell Kwikset!!

I believe that what Goldman is saying is that, even if the handle-set is locked, it is still operable from the inside without unlocking the door.

I don't know offhand whether all Schlage are built that way, but I haven't seen one yet that wasn't

As a not pro I went to my local locksmith told him what I had and what I wanted to do. He gave me advice on the best way. Grin I needed new locks and door handles anyway so bought them then took them still in the box over to be rekeyed. It is very nice to have one key for all the doors AND it was even nicer to know that all those house keys floating around from my teenage sons would no longer work. I think if I ever buy another house the first trip I will make will be to the locksmith.

Hey Dorothy - this post is over 2 years old - I don't think they need any more advice.

My house has 5 Gatehouse locks , the kind with the big drooping handle on the outside, the lever handle inside and the one key hole . Pushing the thumb whatever you call it down on the inside will open the bolt , or you can turn the "whatever you call it" to open the door lock .

So I bought them on clearance at Lowes , maybe ten years ago , and there are two or three different keys for the 5 locks . If I buy the Schlage rekey kit from Lowes , will that work to rekey these locks ?. I am determined to do this myself , not take them to a lock smith .

From what I can find, gatehouse are lowe's brand, which are not made by schlage, and are of lower quality. They use a kwikset style keyway. If it were me, I'd replace them with some better quality locks. But being you bought them on clearance, it seems price was more of a factor than quality.

https://www.reddit.com/r/Locksmith/comments/7p3wqj/gatehouse_rekeying_what_set_to_get/  

They have been in service 10 years . There was a contractor day at Lowes and they had a girl there showing how to reset the pins and she gave me this information , but as a Jarhead , I failed to pay attention . Price is a factor , I reclaimed the home after a divorce , hence the need to rekey , and the lawyer took my money , so yes , I confess , money is an issue .

Schlage typically uses and SC1 Keyway and Kwikset a KW1. Both are fairly common but not interchangable. I would hunt Amazon for a Kwikset rekeying kit after looking at the key and the numbers that are stamped on it.

Thank you . I think I was paying attention to the woman demonstrating rekeying at Lowes , but she did it so fast I missed the technique , and I had not yet begun to research this so it went right over my head . She was telling some other person how she does like 1300 locks at a time for complexes , so I suppose she ha to be very fast .