Add circulating pump for instant hot water and other stuff
For your entertainment and to clog up the great interweb... Actually 3 projects but done at the same time. Add the circulating pump, replace/relocate drain, add timer to pump
Added a circulating pump in bathroom to have 'instant' hot water. Part 1
Couple of recent threads, more recent outing and water was 37° caused me to revisit. I had replaced bath sink plumbing last year and used flex lines so splicing in a pump would be a lot simpler now.
There are a few really good installs threads, some quite elaborate, but in our truck camper the real estate just inst available. So this isn't one. This is just as simple inexpensive without to much attention to detail as a 'proof of concept' project. If it works Ill use- if it doesn't Ill remove, no loss.
Our bathroom sink is maybe 10' run from water heater. To get hot water, especially in the morning, requires running quite a bit of water down the drain. Which we don't..either waste the water or as precious, holding tank capacity. So washing my face I get first hand report of how cold it got during the night. Even though the volume of water in pipe is maybe a cup, it takes considerably more than that before water becomes hot.
This has been on the round to it forever. Adding a circulating pump. I actually bought small $15 pump 2 1/2" years ago to experiment with but never got around to it. One reason is I'm sure it would need at least one check valve which I don't have. Second was I really don't know if pumping hot line water into cold water line will work on the campers plumbing-where main pump or water heater might not let water loop thru closed pressurized system. Mainly, would have to cut the PEX lines to install to find out -which is where I always balked. Having since added the flex lines no longer issue.
The plan. Add tees to bath faucet lines, plumb to circulating pump from hot then into cold line. Power thru momentary switch off main water pump switch (to ensure new pump can only be turned on with water in lines). Seems simple. Picked up 2 Flair-it PEX tees.
Found a small 3/8" FPT inline check valve. Very little pressure needed to open.
The pump has 1/4" threaded outlets but terminates with a 3/8" barb so you can use either. I chose to use the barbs to simplify. Price brass fittings lately?
Adding tee on hot side above existing tee, cold side under as existing is a bit low. Working inside cabinet thru door past the drain a pain. Normally I would drop p-trap, just lazy
I coupled hot tees to decrease height.
Removed existing cold tee, added new one then with short piece of PEX replaced old tee on top. Tee to shower had been installed too low but now sink flex line is against bottom of sink, 12" line too short to loop, needs a longer line (note to self).
Mounted the pump and connected the lines. Check valve on pump outlet. This pump though supposedly self priming won't move air, so its mounted low to retain water in lines or so air wont settle directly at inlet. Really not liking the barbs on the pump. I double clamped but don't trust. Seems a bit soft and there are 2 flash seams. If this works I'll address but as I only have 50% confidence this is going to work and not pulling it all out, not spending a lot of energy now. Pump is mounted to 1/8" luan so it needs a backing board.
Pulled the water pump remote switch out to wire pump.
Added momentary switch, jumpered the water pump switch so either this remote or switch in kitchen feeds other pole of DPDT to energize the momentary. Added leads to plug pump in.
And done...initial bleeding of lines was a bit of a pain. Hopefully once water in lines & pump subsequent bleeds will be easier. Then again I had drained entire system so more air to move than usual plus new pump. Once lines bled then burp the circulating pump with cold faucet open to remove air in front. No leaks. Fired up the water heater.
Once heater shut off with little hope of success, my left hand at top of hot water flex line, pushed and held the momentary switch. Pump is pretty quite. Counted off about 7 seconds I could feel warmth so stopped. Opened the tap HOT WATER! Hokey smoke. I really didn't think this would work. Simple inline pump between hot and cold lines. Pretty stoked.
If I ever have an issue with pump Ill replace with a bit better pump and one with threaded 1/2" outlets and re-plumb with flex lines. Had I known this would work that's what I would have done from the get go. I might have 35 bucks for a what the heck trial but we have Instant hot water.
Left system pressurized with water pump off. Ill check pressure in the morning and recheck time to get hot water. Next morning system still holding pressure, no leaks. Refired water heater, once hot timed the circulating pump and I got 10 seconds to have HOT water at bathroom faucet.
Id want to redo the pump-not liking the clamps, could get rid of some by installing check valve directly to pump. Make mount board. Repaint the inside of cabinet. Maybe later.
Shut off valves would be nice but picked up 2 Flair-it caps for the tees just in case.
And sooner than later:
2 days later pump started leaking at the line on outlet barbs. Slight but leaking. Pulled it all out.
Cut off the pumps barbs and threaded on brass fittings. Check valve directly on pump. Cut a piece of 1/4" plywood to remount the pump on, glued and screwed to wall. Ready to remount but I stopped.
I kept seeing the silly 1 1/2" drain on this little sink. Open the door to this under sink cabinet your greeted with 1 1/2" P-trap. Area inside is fairly large but can barely get a spare roll of TP inside. I don't know why its plumbed as it is. I cant fathom why stand pipe isn't directly behind sink drain, why P-trap is so low. Decided now would be the time since water lines that go over/under are loose to look at changing. If only changing to 1 1/4" p-trap would increase space but looks like I could both raise and rotate. So Off to the hardware...
Wow look at the room...oh-thats not going to work. Need to drop p-trap to get at stand pipe level, sink tail is too short and with longer one puts p-trap almost where it was.
If I cut the pipe coming out of wall might be able to 45° end toward sink. How the heck do I get in there to cut it?...
Added a circulating pump in bathroom to have 'instant' hot water. Part 1
Couple of recent threads, more recent outing and water was 37° caused me to revisit. I had replaced bath sink plumbing last year and used flex lines so splicing in a pump would be a lot simpler now.
There are a few really good installs threads, some quite elaborate, but in our truck camper the real estate just inst available. So this isn't one. This is just as simple inexpensive without to much attention to detail as a 'proof of concept' project. If it works Ill use- if it doesn't Ill remove, no loss.
Our bathroom sink is maybe 10' run from water heater. To get hot water, especially in the morning, requires running quite a bit of water down the drain. Which we don't..either waste the water or as precious, holding tank capacity. So washing my face I get first hand report of how cold it got during the night. Even though the volume of water in pipe is maybe a cup, it takes considerably more than that before water becomes hot.
This has been on the round to it forever. Adding a circulating pump. I actually bought small $15 pump 2 1/2" years ago to experiment with but never got around to it. One reason is I'm sure it would need at least one check valve which I don't have. Second was I really don't know if pumping hot line water into cold water line will work on the campers plumbing-where main pump or water heater might not let water loop thru closed pressurized system. Mainly, would have to cut the PEX lines to install to find out -which is where I always balked. Having since added the flex lines no longer issue.
The plan. Add tees to bath faucet lines, plumb to circulating pump from hot then into cold line. Power thru momentary switch off main water pump switch (to ensure new pump can only be turned on with water in lines). Seems simple. Picked up 2 Flair-it PEX tees.
Found a small 3/8" FPT inline check valve. Very little pressure needed to open.
The pump has 1/4" threaded outlets but terminates with a 3/8" barb so you can use either. I chose to use the barbs to simplify. Price brass fittings lately?
Adding tee on hot side above existing tee, cold side under as existing is a bit low. Working inside cabinet thru door past the drain a pain. Normally I would drop p-trap, just lazy
I coupled hot tees to decrease height.
Removed existing cold tee, added new one then with short piece of PEX replaced old tee on top. Tee to shower had been installed too low but now sink flex line is against bottom of sink, 12" line too short to loop, needs a longer line (note to self).
Mounted the pump and connected the lines. Check valve on pump outlet. This pump though supposedly self priming won't move air, so its mounted low to retain water in lines or so air wont settle directly at inlet. Really not liking the barbs on the pump. I double clamped but don't trust. Seems a bit soft and there are 2 flash seams. If this works I'll address but as I only have 50% confidence this is going to work and not pulling it all out, not spending a lot of energy now. Pump is mounted to 1/8" luan so it needs a backing board.
Pulled the water pump remote switch out to wire pump.
Added momentary switch, jumpered the water pump switch so either this remote or switch in kitchen feeds other pole of DPDT to energize the momentary. Added leads to plug pump in.
And done...initial bleeding of lines was a bit of a pain. Hopefully once water in lines & pump subsequent bleeds will be easier. Then again I had drained entire system so more air to move than usual plus new pump. Once lines bled then burp the circulating pump with cold faucet open to remove air in front. No leaks. Fired up the water heater.
Once heater shut off with little hope of success, my left hand at top of hot water flex line, pushed and held the momentary switch. Pump is pretty quite. Counted off about 7 seconds I could feel warmth so stopped. Opened the tap HOT WATER! Hokey smoke. I really didn't think this would work. Simple inline pump between hot and cold lines. Pretty stoked.
If I ever have an issue with pump Ill replace with a bit better pump and one with threaded 1/2" outlets and re-plumb with flex lines. Had I known this would work that's what I would have done from the get go. I might have 35 bucks for a what the heck trial but we have Instant hot water.
Left system pressurized with water pump off. Ill check pressure in the morning and recheck time to get hot water. Next morning system still holding pressure, no leaks. Refired water heater, once hot timed the circulating pump and I got 10 seconds to have HOT water at bathroom faucet.
Id want to redo the pump-not liking the clamps, could get rid of some by installing check valve directly to pump. Make mount board. Repaint the inside of cabinet. Maybe later.
Shut off valves would be nice but picked up 2 Flair-it caps for the tees just in case.
And sooner than later:
2 days later pump started leaking at the line on outlet barbs. Slight but leaking. Pulled it all out.
Cut off the pumps barbs and threaded on brass fittings. Check valve directly on pump. Cut a piece of 1/4" plywood to remount the pump on, glued and screwed to wall. Ready to remount but I stopped.
I kept seeing the silly 1 1/2" drain on this little sink. Open the door to this under sink cabinet your greeted with 1 1/2" P-trap. Area inside is fairly large but can barely get a spare roll of TP inside. I don't know why its plumbed as it is. I cant fathom why stand pipe isn't directly behind sink drain, why P-trap is so low. Decided now would be the time since water lines that go over/under are loose to look at changing. If only changing to 1 1/4" p-trap would increase space but looks like I could both raise and rotate. So Off to the hardware...
Wow look at the room...oh-thats not going to work. Need to drop p-trap to get at stand pipe level, sink tail is too short and with longer one puts p-trap almost where it was.
If I cut the pipe coming out of wall might be able to 45° end toward sink. How the heck do I get in there to cut it?...
