The shower does not get hot so i took pressure balance unit apart and cleaned also took hot limit stop off .still not hot rest of sinks in house are hot and furnace right under shower,what do you think it could be.

Are you wanting to change/switch the hot and cold range of the shower or the temperature max and min? As for the range, the Monitor pressure balance valve may be having build up or problems. This valve controls the mixture of hot and cold water. To fix this, you will need to turn off the water supply, take the pipes apart and clean out the valve (I would recommend a professional). As for the max and min, you may just need to check the water heater pressure in your house. It may not be the faucet at all.

Elisa Jed ' http://www.ryansallglass.com/

There should be a hot water limiter behind the knob on the shower - shingle handle, undo the handle and move the adjustment to allow more hot water. Not familiar with mira discovery mixer

Screw off shower head-obstruction in water saver disc or screen,piece of rubber or rust

The Delta shower has a rotational limit stop designed so that when another fixture is activated, such as a toilet or dishwaser, the water does not go to extreme hot or cold. The reason for this is that the Delta shower unit is not pressure balanced or does not contain an anti scald device. The pdf document below will show how to adjust the water tempature if you feel it is too cold. Please use caution as it is probably set the way it is to prevent scalding.

http://www.deltafaucet.com/media/Product_Tech_Docs/Maint_Installation/50001to80000/51975RevH_4.15_15e05.pdf

that pump is likely to be a hot water return pump not a booster pump. it sound like a large property so its likely the hot water system requires balancing to get the hot water to the extreme areas. If all the hot outlets have some form of isolation valve try closing all but the affected areas and see if hot water comes out. If so only open the closed outlets enough to give you reasonable flow. This hopefully will force the hot water to the affected areas.

the anti scold control, must be adjusted.You need to turn the water off for this,remove the handle,and the chrome sleeve,it is usually located just under the handle

This is a common problem with this type of shower mixer valve. They are not very good at regulating with pressure change. Your options are somewhat limited to not flushing the toilet or using any other taps when in use, repalce the mixer valve for a modern ceramic unit or installing a 2 vane hot & cold shower pump.

From what you've described, it's got to be a block between the main supply line and the shower head.

If you have never used this shower after its installation, it's possible that the temperature limit stop is set too low.

Otherwise, either the hot water valve or the balance spool need maintenance. The instructions on pages 4-6 of the link below should be helpful for correcting the problem.

http://www.moen.com/shared/pdf/instruction_sheets/INS162E.pdf

check for sediment in your valve body... sometimes sediment can build up particularly in hot water pipes and that can cause the pressure balancing function of the valve to limit total hot water and therefore you cant get it hot enough... here is a link to what I think is the proper valve and the instructions for installing it... you'll want to follow the instructions for flushing and pressure testing... if you have good pressure at the thermo body then you might try adjusting the hot limit stop also covered in the document linked below...

http://www.hansgrohe-usa.com/JP/hrgh0264.pdf

Hope theat helps...