I had two showers that were acting up. The first shower failed to produce hot water, the temperature was only lukewarm. The second shower was leaking, and had gradually worsened from a slow drip to a constant stream of water. I called Heritage Plumbing & Heating in Salem NH. They sent out a guy who took a cursory look at both showers, and then quoted me a price of $1800. I asked why so expensive, and he said he didn't feel comfortable installing a new cartridge, and would need to cut holes in the walls to put in brand-new valves. I then called a local plumber who installed a new cartridge in under 5 minutes in one shower, and did in fact have to install a new valve in the second shower. However, the price he charged for parts and labor was $400, and he was done in about 2 hours. Bottom line, don't trust Heritage Plumbing & Heating. They severely overcharge.