I adjust the temperture in 2 weeks ago . It get very hot .but now the water is hot as before . I don't know what's the reason. Probably the cartridge is something wrong.

Yes you need to replace as a complete Cartridge Repair Kit. Once they wear, you can't fiddle with them and make them better.

Hi Marshall,

Do you mean that no hot water is reaching the shower, or do you mean that no hot water is coming out of the shower. The answer to this will determine where the problem is.

If no hot water is reaching your shower, then there is probably a problem with the boiler or the pipe is blocked. You can easily test this. You can turn on other faucets in the bathroom to check whether any hot water is reaching those.

If the problem isn't with the boiler and the shower is in fact receiving hot water, then the problem will be with the shower mixer valve, specifically the thermostatic cartridge. The cartridge controls water temperature. The inner workings of the cartridge move up and down to adjust the amount of hot and cold water entering the cartridge. If it has seized up, the moving part can get stuck in a certain position. It sounds like this could be the case with you and therefore replacing the cartridge should in theory fix the problem.

Hope this helps. Shower Thermostatic Cartridge Spares

You know that you have to adjust valve lash when the engine is hot right?

Temp control is only accomplished by moving handle to desired position. If your asking is the hardware that in behind the single lever going to allow for adjustments, then the answer is NO. I installed the same into one of my bathrooms several years ago and I know what I am talking about. The single handle on that type on mine starts off then cold to hot. Problem is I wait for hot water to max so I can adjust it down to a comfortable temperture to prevent being burned. I refuse to buy one for other tubs. The 2 handles make temperture much easier with less wasted water used until its hot. Remember if you decide to replace with a two lever model then you will have to replumb the pipes for a two handle hardware unit (thats the stuff behind wall that your single handle goes into to which is currently plumbed for a single handle hardware unit.)

Assuming that you have sufficient hot water, you need to adjust the Scald-Guard valve. It's usually quite easy to do. The intent is to limit the amount of hot water that can be fed to to shower head or tub spout. On the 1300/1400 series faucents there is a disk behind the faucet knob/lever called the rotational limit stop. Remove the knob/lever, either by popping the cover off the knob and removing the screw with a Philips head screw driver, or removing the handle with an allen wrench. Next adjust the rotational limit stop disk clockwise to increase the limit on hot water flow. Delta claims each tooth you click past clockwise will increase the maximum water temperature by 6 degrees F.

Delta has a great FAQ on their web site. As of Jan 30, 2011, this link is valid:
http://www.deltafaucet.com/customersupport/faq/Water+Temperature/

If the rotational limit stop disk is already turned to the maximum point (clockwise), then you may have a hot water flow problem (either with the cartridge or to or in the manifold). The cartridges require a little more know-how to replace. You'll need to shut off the main water valve prior to removing the old cartridge. There are a couple of places that detail how to replace and/or service the cartridges, including a short video on youtube. I can post more details on this if you find you need to replace the cartridge.

If you aren't getting any error codes, then the heater is probably doing its job. Your problem is probably somewhere in your plumbing system. The most common reason you get this sort of problem is due to cold water mixing in the hot water system. There are a number of causes for a "cross connection" :

-Faulty check valve
-Missing check valve on reciculation return line
-Faulty shower cartridge
-Thermostatic mixing valve set too low
-Faulty thermostatic mixing valve
-Faulty anti-scald valve

The easiest way to confirm a cross connection is to: 1) shutoff the cold water entering the tankless heater 2) open hot water valves around the house. If you still have water flowing at your hot water fixtures, then you have a cross connection.

Do your sinks have a hot and cold handle or just one handle. how old are the faucets. If they are very old.the first thing i would do take one faucet out and replace cartridge.

They are clogged. Soak the print head in hot tap water for a few seconds, dry and re-insert. Then run the cleaning program. If this does not work, then you need new carts.

Geno