Plumbing Suggestions Requested - How Can This Fit?

I want to add a thermostatic valve to my shower, so we don't get scalded and frozen, and less water is wasted getting the temperature right. I want to connect the output to both the existing hot and cold faucets so it does not matter which you use.

The plumbing is behind this panel and whatever is added needs to fit behind the panel.



I think I have figured out how to connect the mixing valve to the existing faucets, with a combination of fittings as shown to make a sort of "manifold". The mixing valve is as low and to the rear as possible to leave room for other added plumbing. Note that all the fittings have not been fully tightened down as I am just doing a check fit first.



My problem is how to connect up the two supply lines to the mixing valve. The supply lines will be disconnected from the existing faucet fittings and the new fittings from the "manifold" will be connected. Connections are needed for the blue and red lines in the photo. What would be best to do this? It seems that using more elbows and fittings won't get me there and easily fit in the room that is left. It seems like they would quickly fill up the space and get out of hand.

Suggestions welcomed.

Regards,

Mark

Apologies for the poor photoshop, but hopefully you get the idea...

1) I don't see why you've put all that pipework in to have the hot water going to both faucets. I would personally leave the cold feed pretty much as it is but insert a T piece in which goes to the thermostatic valve on one side and to the cold faucet on the other.

2) This just leaves the hot feed needing to go into the thermostatic valve which I would do by running a flexible hose roughly where you have marked your red line.

It would look something like this



The sort of flexible hose I was thinking of was something like this one, but you could equally just use your existing compression fittings with a bit of hosepipe (you can get food grade stuff if that's a concern)



Hope that makes sense.

Either way, I think flexible pipe is your solution here rather than lots of rigid joints. It also creates fewer joints which could potentially fail and leak. Lots of RV places sell blue and red hose if you wanted to colour code it.

Another option is to put the mixing valve on the water heater outlet. Then you just set your shower to full hot.

Also, adding a check valve on the cold water feed to the shower helps with the scalding quite a bit.

I'm considering putting the output on the hot only. The flexible hose seems like the best solution to fitting things in no matter how it is done. We do want very hot water available at the kitchen and bathroom sinks, so we really want the mixing valve on the shower only.

Regards,

Mark

I found that between the mixing valve on the water heater, and the check valve, shower temperatures are much more consistent. You could also tap the sinks off before the mixing valve, but still have the hot water regulated on its way to the shower. If you set the hot water to about 110F, that would let you mix in a small amount of cold if you wanted a cooler shower.

Midwestdrifter said:

I found that between the mixing valve on the water heater, and the check valve, shower temperatures are much more consistent. You could also tap the sinks off before the mixing valve, but still have the hot water regulated on its way to the shower. If you set the hot water to about 110F, that would let you mix in a small amount of cold if you wanted a cooler shower.

Click to expand...

Unfortunately, there is even less room by the water heater:



The red pipe at the top right disappears behind the water heater into the wall to come out by the shower and I believe also gets to the sink above the water heater. The pipes that head left then go down and under the floor to the kitchen sink.

So, I think whatever is done has to be by the shower behind the service panel, but I am considering only feeding the temperature controlled water to the hot faucet only, which may save some piping. If I do that, I will have a check valve in the cold water line to the shower faucet. You can see there is some flexible line by the water heater.


Regards,

Mark

I think I will do the following, pretty much as Sparkplug suggested with addition of a check valve. I will use flexible tubing as required but this arrangement lines up much better and leaves room for more piping. I am hoping the original PEC can bend some. I've offset the valve so the Hot in and Hot out pretty much line up, making moving the original line easier.



Regards,

Mark

If you warm the pex up to 250F it bends some. Just don't do it repeatedly, and don't kink the line.

Here is how it all fits. The metal protectors on the PEX helped, they could move quite a lot and keep it from kinking.



I know the attachment of the flex tubing to fittings with one barb is not deluxe, but they did the same thing other places and it has held up for 12 years.

No leaks so far and it works fine, warm water all the time.

Regards,

Mark

I have some questions during installation....I purchased the exact same one.

Trying to decide were to put it. Should it be regularly available. Once adjusted do you have to continue to set the temperature? The instructions I received were a little vague about the red button. From what I gather you use the red button to adjust temperature readings to display more accurately.