my shower is not hot enough

I just moved into a house with single handled shower valves in both bathrooms. They are the type that start cold and as you turn knob water gradually switches to hot. Problem is that to get hot water you must turn all the way and hot water pressure is very low. Most of the turn produces cold water at very good pressure but as soon as you get to the warmer water temp the pressure disappears,this is in both showers but not in the two handled sink faucets in the kitchen and bathrooms. Water heater is almost new and turned up to 135 degrees. Water is plenty hot eveywhere but showers. No marks to identify manufacturer of valves and can't find any that look the same. Could whatever prob they had with the old water heater somehow affect this type of valve but not the two handled?

Many showers today have a mechanical High Limit stop on the hot side. They are adjustable. If you remove the handle and see some parts that look like gears and cogs, this is it. There is usually a little arrow showing to move a piece for HOTTER or COLDER.

If you can identify the brand, you can probalby find a diagram on their website.

The faucet may also be "pressure-balanced" for scald protection, and in this type of faucet there is a moving balance spool inside. This can get stuck, causing "mostly cold" or "mostly hot" symptoms. On some brands this can be removed, cleaned and lubricated. On others, the part must be replaced.

pulled off the handle and under was a plastic shield covering a metal disk. 2 screws (1 phillips, 1 slotted), seem to hold the shield in place but the slotted was 3 inches long and the phillips just turned and turned.

Can you post a picture?

here is a pic

I notice since I posted the picture of this shower valve noone is replying anymore. Is this because no one has even a clue as to what brand this could be or did everyone just lose interest in my quandry? Any clues where else besides this forum where I could look? Any help would help. No help is no help at all. Wow, thats deep. Jimbo? Plumguy? Any body? Little help?

We didn't lose interest. We are more interested than ever! But, it is not ringing any bells with me. Someone will recognize it. Please be patient.

Thanks Jimbo, I was about to look into having a plumber replace the valves just to settle the issue but don't want to spend the money on a rental I do not own. But then I have to live here and can't live without a decent shower. So patient I will be and the search shall continue. If I find the answer outside of this forum I will post the answer for you guys so we all can sleep better at night.

A rental you don't own? I know if I was the Landlord - and my tenant came to me with this complaint.... I would feel obligated to have it corrected.... at my expense.....

its not looking good

hi. im jimbo55 with the same shower cartridge as you. we must be stuck with a bogus brand. if you are a little mechanical you can take the cartridge apart. ive done it twice. there are like cermanic parts that break off and either clog or keep it from shutting off completely. if you try this please dont blame me if you are no shower as opposed to cold shower.