water pressure

[timplemons]

main line is 3/4., shower supply tees off into a 1/2 inch supply and runs nearly 25 feet then up from basement to shower, would this be why there is low flow to the shower,, there are 2 separate shower head that you select with a diverter valvle

 

[Beni]

If your running two shower heads off of 1/2" lines then it could be a problem. Another issue is that many of the newer shower heads need 30-40 psig at the valve due to the pressure drop through the flow control device. In some areas that might be marginal.

Some shower heads have a flow control have a plastic part that can be removed or drilled through to solve a low pressure issue.

 

[timplemons]

thing is theres not alot of pressure even with the head off, there newer lines thats why I was think it the 1/2 inch for that long of a distance

 

[Beni]

A 1/2" line would give you 5-6 gpm without a shower head which should be enough. What brand shower valve do you have. Are both the hot and cold water valves serving the house fully open. Wondering the the shower valve is a pressure balanced type with a stuck piston. That could cause a low flow rate.

 

[stevemachine]

Personally what I've done before is if you have access to the back side of the tub I would turn the water off to your house, cut into the line, valve it off both hot and cold and turn the water back on. Then grab a bucket and open the valve to see if the pressure is good or not, that way you can start eliminating stuff. I've made the mistake before thinking it was the shower valve and it was actually the line coming off the header was plugged with debris. What material is the water line? Pex?

 

[stevemachine]

Plus if the pressure is ok then no big deal, now you have valves which makes your shower valve more serviceable

 

[IFIXH20]

main line is 3/4., shower supply tees off into a 1/2 inch supply and runs nearly 25 feet then up from basement to shower, would this be why there is low flow to the shower,, there are 2 separate shower head that you select with a diverter valvle

thing is theres not alot of pressure even with the head off, there newer lines thats why I was think it the 1/2 inch for that long of a distance

Is this the same shower with the Grohe shower valve ?

 

[timplemons]

yes this is grohe shower

 

[DetroitRob]

Are there inlet screens on the mixing valve that could be clogged?

 

[IFIXH20]

Remove the valve handle and trim plate. Post some pics of valve.

 

[timplemons]

cleaned mixing valve. completely

 

[IFIXH20]

Timplemons, did you clean the valve stops/stop checks ? I know you cleaned the cartridge , but your problem could be at the stops/stop checks. You should have one of three valve type, Grohe 34-434 , 34-436 , 34-485
google those numbers to see which valve you have. Not saying that this is your problem , but 99 percent of pressure & temp problem with these valves are from the cartridge or stops/checks , the stops/check has screens on them just like the cartridge, they need to be removed and cleaned as well. Not sure if you did this already.

 

[timplemons]

ty are the checks built into the valve cartridge itself ?

 

[timplemons]

definatley is a 34-436 valve

 

[IFIXH20]

The stops are in the valve body not the cartridge. Use the site below to see a exploded view and part list of your valve. Locate the stops on the exploded view then locate on your valve for removal


http://www.grohecatalog.com/product/34436-grohmix

 

[timplemons]

ty ,so behind these stop your saying it may be clogged right ?

 

[DetroitRob]

That is correct.

 

[IFIXH20]

Look at the exploded view & parts list of the site previous posted , find #9 which is the stops with screens, remove & clean the stops also check inside of valve when stops are removed.