Mix & match port size on new manifold setup

[DeRanger]

Hi Pros, I’m doing a master bath reno (kitchen to follow) and looking for advice on hot/cold water manifolds. I'd be happy to pay someone local for a quick consult. The main point of my post is can I buy or should I even make a manifold with 1/2" and 3/4" barbs? Some runs are pretty long on 3/4" and I am not sure I can run 1/2" direct to everything without a full gut of the house.

I’ve got a few issues and want to do it right:

• Main shutoff valve leaks (O-ring/packing)— need to shut off at the street for any work.
• Hot water shutoff valve is leaking.
• Occasional, water drops in HW tank pan — possibly the valve, but tank is 10+ yrs old.
• HW tank pan isn’t drained to the sump.
• Noticed hot water pressure fluctuations in master bath — I suspect poor barb points or sizing.

Plumbing layout (See Drawing & Pics):

• HW heater has a dedicated ¾” cold supply from 1” main (Img-01). Hot output is T-’ed with ¾” toward kitchen + Original master bath in one direction, and then ¾” toward Laundry + Full Bath + ½ bath the opposite direction (Img-05).
• Multiple barb sizes and materials. 1” Cold copper supply and Hot output is ¾” copper. But then ½” PEX-A barbs (shower, sinks) come off the ¾” cold supply for the HW tank, not the 1” main supply (Img-03).
• New Master bath is roughed in with ¾” hot/cold (2 sinks, 2 shower heads, future steam) but currently fed from a size-drop from ½” H & C feeds downsized probably somewhere in the soffit (Img-01).
• Planning to install manifolds with shutoff valves (Img-06), replace tank and leaking shutoff, and tie in HW pan to the sump (Img-07 & 08) — but need advice on the best way to do it and if mixing ¾” & ½” barbs is OK for manifold.

Any thoughts or feedback appreciated — and if someone’s willing to stop by, I’d gladly pay for your time.

 

[tafisa]

Hi Pros, I’m doing a master bath reno (kitchen to follow) and looking for advice on hot/cold water manifolds. I'd be happy to pay someone local for a quick consult. The main point of my post is can I buy or should I even make a manifold with 1/2" and 3/4" barbs? Some runs are pretty long on 3/4" and I am not sure I can run 1/2" direct to everything without a full gut of the house.

I’ve got a few issues and want to do it right:

• Main shutoff valve leaks (O-ring/packing)— need to shut off at the street for any work.
• Hot water shutoff valve is leaking.
• Occasional, water drops in HW tank pan — possibly the valve, but tank is 10+ yrs old.
• HW tank pan isn’t drained to the sump.
• Noticed hot water pressure fluctuations in master bath — I suspect poor barb points or sizing.

Plumbing layout (See Drawing & Pics):

• HW heater has a dedicated ¾” cold supply from 1” main (Img-01). Hot output is T-’ed with ¾” toward kitchen + Original master bath in one direction, and then ¾” toward Laundry + Full Bath + ½ bath the opposite direction (Img-05).
• Multiple barb sizes and materials. 1” Cold copper supply and Hot output is ¾” copper. But then ½” PEX-A barbs (shower, sinks) come off the ¾” cold supply for the HW tank, not the 1” main supply (Img-03).
• New Master bath is roughed in with ¾” hot/cold (2 sinks, 2 shower heads, future steam) but currently fed from a size-drop from ½” H & C feeds downsized probably somewhere in the soffit (Img-01). hair transplant turkey
• Planning to install manifolds with shutoff valves (Img-06), replace tank and leaking shutoff, and tie in HW pan to the sump (Img-07 & 08) — but need advice on the best way to do it and if mixing ¾” & ½” barbs is OK for manifold.

Any thoughts or feedback appreciated — and if someone’s willing to stop by, I’d gladly pay for your time.

just answer ChatGPT said: Yes, you can use a mix of ½" and ¾" barbs on a manifold. Just make sure ¾" is used for longer runs or higher-demand fixtures, and ½" for short runs or single fixtures. Don't reduce pipe size too early in the run. Your plan to install manifolds with shutoffs, replace the leaking tank and valves, and tie the pan to the sump is solid.

 

[Sponsor]

 

[DeRanger]

just answer ChatGPT said: Yes, you can use a mix of ½" and ¾" barbs on a manifold. Just make sure ¾" is used for longer runs or higher-demand fixtures, and ½" for short runs or single fixtures. Don't reduce pipe size too early in the run. Your plan to install manifolds with shutoffs, replace the leaking tank and valves, and tie the pan to the sump is solid.

Thanks for confirming.

Couple follow up questions:
- Do you know of a quality manifold manufacturer (off the shelf) with mixed barb sizes or would I have to make it from scratch?
- Any thoughts about an quality way to tap the drain into the sump? I am sure I gotta put a check valve inline, but how do I tap the hole into the plastic sump tank?