Grohe Integrated 1/2'' Shower Thermostatic Rough-In Valve With Stops - 3412 - Answered Questions & Fixed issues

the temp, control valve is getting to hot!!! there for only let so much hot water go thru, did you take the inner parts out when soldering this in, if not you might have damaged it, and if so need to replace the cartdrige

Get a couple of pipe wrenches for parts that you can unscrew, a torch for copper pipes because you can unsweat the solder and pull the pipes apart. You can take these to the recycling center and get a little money back for all your hard labor. Or take a receipt ocarina saw with a few metal blades and cut them into pieces. If you use a torch don't burn down the house, if you use a reciprocating saw don't cut any electric lines. Also if the pipes are insulated there are special precautions you need to remove it

valve should have a gear like deal under handle that may need to be adjusted

Replace the rough in valve

you need to change the cartridge, it is a temp control and is going bad so it keeps you from burning yourself it is like a mixing valve and is givng more cold water, that way you don;t get burned,,

MAy I get the model # of the valve that you need to remove the cartridge from to help you more.

Having looked at the diagrams of the valve I not sure the handle is tight on your stem an is not turning the valve stem.
Look at that and if that's not it I will try to help.

he probably put it together wrong.
there is usually a blue gasket inside for testing purposes, if that is not removed, the valve will not turn off.

If you but a trim kit it has the installation instructions for the trim with it. Did you open the stops to let water in?

It has been a while since I have worked on a Grohe, But if it has a built in scald gaurd or thermo cartridge, it may be sticking and need to be replaced.

well you can do a 3 way shower valve , or a mixing valve with 2 control valves. or you can do just to regular shower valves one for each of the heads you want one for the rain and one for the shower head. this way is cheeper and you can have one on hot water and the other cold water or the other way around or both the same temp.

The thermostatic mixing spool cartridge may be worn out. The low water pressure may indicate sediment in the cartridge as well. This can be easily removed by hand tools

hi capacity of tank ? temp set low demand to much

Do you mean the other faucets in the house are hot and only the shower is warm? If so there is an anti-scald adjustment on the faucet that needs to be turned up a few notches. Havent adjusted a Grohe faucet but most faucets you rmove the handle and behind the handle is a nothced adjustment ring that prevents the faucet from getting too hot. This ring, or stop, is pulled out and twisted clockwise(or counter clockwise to set higher or lower max temp, then pushed back. maybe you can look up grohe to see which way ring or stop adjusts for hotter water.

There is a chance there is mineral deposits in the showerhead openings. You can try products sucha as limeaway by unscrewing the showerhead , soaking in the limeaway for a few minutes and rinsing with water. You may have to repeat this a few times to get it clean.

adjust the thermostat setting on your hot water heater. They are located in different configurations. Consult your water heater manual

from a plumber all hot and cold connections on all major showers are hot on the left and cold on the right just like the taps on your sink or washbowl

norm cover levers off go round cover at four points

if you pull the handle off all the way back to the valve body there is a little black stopper around the cartridge body that you can adjust by pulling it out and sliding around the cartridge body this enables people to just turn the handle to one setting and jumpping in to their favorite temperature. in your case it doesn't allow you to have any cold water. so turn it one way see if you get what you want or try the other or some of them you can even just take the darn thing out and not even have to worry about it

Hi,

If the hot and cold are fitted the wrong way round then the thermostat on the shower unit cannot operate properly!

Most thermostatic mixer showers have a 'bi-metallic' thermostat, if you supply the hot to the cold and vice versa IT WILL NOT WORK.

It is like wearing the left shoe on the right foot and the right on the left! It doesn't work.

Re-install the hot and cold to the correct supply, and this will sort it.

I hope this helps.