Shower mixer replacement

[Phil23]

I need to replace two shower mixers as one has seized the other on the way.
I am a 12v system, 25lb Jabsco pump and have a pressure cylinder. Looking at mixers I am somewhat confused do I need a mixer for low and unequal pressure. Unable to identify model of existing units as they have been installed in an inaccessible location and will have to cut out!!!!!

[O C Diver]

First, posting pictures of what you have makes it much easier to offer alternatives.

For my boat, I prefer the single mixing valve shower control. So I installed a Moen home style.



Ted

[mvweebles]

A picture would definitely help, at least a description of whether a single handle like pic in previous post or two handles.

Your shower valve is almost assuredly a regular home-style shower valve. 12v or lower pressure have no bearing on shower valve selection.

I am also confused by description of being "seized.". The guts of the valve is a cartridge that can be removed and replaced. These are typically brass in older units, ceramic or plastic in newer ones; with o-rings. There is nothing to seize (per se) but can be cleaned and lubed. Or the insert cartridge can be replaced On older or obscure valves, you can often take the cartridge to a specialty plumbing store (the old style ones, not a Home Depot).

Random website explaining replacing shower valve cartridge.

https://www.thisoldhouse.com/bathroo...ower-cartridge

Good luck.

Peter

[Comodave]

On our last boat I replaced almost all of the faucets and shower head. I used standard household faucets and a shower mixer and handheld sprayer from Scandvik.

[Phil23]

My comment Seized refers to the inability to turn the handle/cartridge in any direction the mixer is a single tap version with a brass cartridge. The brand is Dorf and 20+ years old. It has become gradually stiffer in recent times. I have 2 units doing the same thing

[syjos]

I use Hansgrohe thermostatic shower valves. Instead of utilizing water pressure changes to regulate water temperature, the Hansgrohe does it with a thermostatic sensor.

Almost all domestic shower valves use the pressure method.

A thermostatic shower valve has one knob for adjusting temperature and another for regulating flow.

These types of shower control work great on boats and RV's that use pumps. The pumps create variable pressure in the water system which create uneven water flow and temperature.

With the thermostatic shower control, no more scalding water when another faucets is opened while showering.