Pressure Switch for booster pump

[Wet_Boots]

There are 'anti-scald' shower valves that take care of pressure imbalances without your having to do anything special in the water supply. If it were my requirement to achieve unvarying downstream pressure, then I'd create a 70-90 psi supply, and install a PRV downstream of the pressure tank, and it would probably have to be set no higher than 60 psi to be truly effective, since there are losses in a PRV to account for, even if the PRV is an expensive pilot-operated type. For just the shower temperatures, pumps and PRVs are not where you should be spending your money. An anti-scald shower valve and a modern massaging showerhead can do good work without needing high pressures. A simple jet pump and pressure tank and CSV will get you as close to a constant operating pressure as you really need.

[Bob1000]

There are 'anti-scald' shower valves that take care of pressure imbalances without your having to do anything special in the water supply. If it were my requirement to achieve unvarying downstream pressure, then I'd create a 70-90 psi supply, and install a PRV downstream of the pressure tank, and it would probably have to be set no higher than 60 psi to be truly effective, since there are losses in a PRV to account for, even if the PRV is an expensive pilot-operated type. For just the shower temperatures, pumps and PRVs are not where you should be spending your money. An anti-scald shower valve and a modern massaging showerhead can do good work without needing high pressures. A simple jet pump and pressure tank and CSV will get you as close to a constant operating pressure as you really need.

The source of hot water is an INSTANT gas boiler ( dont know if you r familiar in USA with that type of boilers) which turns on when you open the hot tap then you adjust the shower water temperature by just adjusting the mixture of cold to hot water . The thing is that you have to keep reasonable hot water tap opening otherwise the boiler will shut off .
This setting is VERY sensitive to pressure fluctuation because when the pressure goes down near to cut in pressure the boiler would turn off and you get cold water shock lolll then you have to keep changing the mixer handel to compromise between keeping the boiler on and the water temperature, while if the pressure is constant then you just set the mixer handel to one position during the whole shower duration.
I hope now that you appreciate the problem here lolll

Would that anti- scald valve solve this problem? and where you should fix them?

I already have bought the Pressure Reducing Valve but ould go for the anti scald if it is more practical

[Wet_Boots]

http://www.terrylove.com/forums/forumdisplay.php?f=5 is the Showers & bathtubs forum, and you can get best advice there. Supply all the information, including your location, which should already be in your user profile. You really have two separate issues, one of pressure, perhaps, and one of shower temperatures.

[Bob1000]

http://www.terrylove.com/forums/forumdisplay.php?f=5 is the Showers & bathtubs forum, and you can get best advice there. Supply all the information, including your location, which should already be in your user profile. You really have two separate issues, one of pressure, perhaps, and one of shower temperatures.

Will do , thank you very much for your help and your time !

[Gary Slusser]

The source of hot water is an INSTANT gas boiler ( dont know if you r familiar in USA with that type of boilers) which turns on when you open the hot tap then you adjust the shower water temperature by just adjusting the mixture of cold to hot water . The thing is that you have to keep reasonable hot water tap opening otherwise the boiler will shut off .
This setting is VERY sensitive to pressure fluctuation because when the pressure goes down near to cut in pressure the boiler would turn off and you get cold water shock lolll then you have to keep changing the mixer handel to compromise between keeping the boiler on and the water temperature, while if the pressure is constant then you just set the mixer handel to one position during the whole shower duration.
I hope now that you appreciate the problem here lolll

Would that anti- scald valve solve this problem? and where you should fix them?

I already have bought the Pressure Reducing Valve but ould go for the anti scald if it is more practical

I think the on off is controlled by water flow, not pressure. Otherwise when the pressure is high and the water is off, you turn the water on the pressure would have to fall very quickly to turn the heater on. And that's is what you think happens but, is it pressure or flow? So a flow switch would be a better choice to control the burner. And the range of flow gpm should be adjustable at least some. So all you may have to do is widen it. Another thing is the temperature settings; on/off of the burner must be controlled and and you may be able to adjust them tighter so the water doesn't get so hot or cold.

If I'm right an anti scald mixing valve is going to control flow but not pressure.

[Bob1000]

I think the on off is controlled by water flow, not pressure. Otherwise when the pressure is high and the water is off, you turn the water on the pressure would have to fall very quickly to turn the heater on. And that's is what you think happens but, is it pressure or flow? So a flow switch would be a better choice to control the burner. And the range of flow gpm should be adjustable at least some. So all you may have to do is widen it. Another thing is the temperature settings; on/off of the burner must be controlled and and you may be able to adjust them tighter so the water doesn't get so hot or cold.

If I'm right an anti scald mixing valve is going to control flow but not pressure.

I am 100% sure that m problem would be solved if I can maintain constat pressure during shower with no fluctuation between cut in and cut out pressure , simply because when I manually keep the pump running continously during shower I can adjust the hot and cold water taps to give nice water temperature and that remains constant as long as the pump is running and no body played with another faucet in the house , it can lat forever like that

[Gary Slusser]

Ok, you're sure and I'm sure you're sure it is controlled by pressure but how is that working for you? It may be controlled by flow and I'm sure you aren't sure it isn't.

And there may be an adjustment on a flow switch so check and see fer sure because this narrow differential pressure switch thing isn't working well at all or you wouldn't be here asking for help with it, and as you see everyone says it won't work. And us guys have worked on a lot of pumps and switches for decades.

A PR valve won't work on your booster pump system either and now you're looking at a mixing valve but that doesn't keep your pump running or provide the narrow pressure range to work, so what's left to choose from IYO? I suggest looking at the heater and adjusting the temp settings or a flow switch or pressure adjustment. I'm sure you could humor me and at least look and prove there is none. I'd feel better if you would.

[valveman]

You are both right! Instant water heaters must have a certain amount of flow to keep the burner going. However, the flow is dependent on the pressure at the shower head. Using a 40/60 pressure switch, the size of the holes in the shower head allows more water out when the pressure is at 60, than it does when the pressure is at 40.

Actually, adjusting the mixture handles on the shower probably does no good at all to get the burners back on. The shower head is just not letting out enough water to light the burner until the pump comes back on at 40 and brings the pressure up to 45 or 50.

Make sure your pressure regulator has a thermal bybass, then install it on the house line and set it at 50 PSI. Then set you pressure switch as close as you can to 60/80. This is not good for the pump but, will give you a constant 50 for the house. If the shower head is not letting out enough water at 50 PSI, you need to open it up.

I assume you have already removed the little "water saver" washer from the shower connection line. If not, do so, and that may solve your problem. After removing the washer with the small hole, the only way to get more flow is to drill out larger holes in the shower head.

[Gary Slusser]

ummmm So I took the time to look up tankless water heater + control in Google.

I see you are supposed to set the temp range and then the entering water temp and then the GPM FLOW RATE IN GPM. Of course that is with one brand, the Rinnai, others may vary.

You can start here.
http://www.foreverhotwater.com/control-mc-100v.php

http://www.foreverhotwater.com/temp-setting.php#

http://www.foreverhotwater.com/operate.php

And I scanned/read about 85% of the link below; it's long. It defines the problems with tankless water heater design over the last 30+/- years. My first experience with one was in 1963 in Holland; that's 45 years ago. It was flow and temperature controlled. Anyway, I have not seen water PRESSURE mentioned in any of this... only flow gpm and temp.

So I've been thinking that fooling with this 2 hp booster pump and now high range pressure switch without getting into the flow and temp settings is simply wrong and now I have some third party info to back up my previous guesses. The last link below is from another brand and the article goes back to day one in tankless water heater design and the problems in getting it to work and the causes of the problems.

From all of this I can say without guessing that boosting your water pressure as high as you have is making your problem worse and to get it to work as Valveman suggests, and he mentions the pump problems in doing so and I agree with him, it will ruin your pump fairly quickly. The pump will cause your electric meter to spin at a high speed every time you use water. Here's the best link for the description of tankless heater designs etc.

http://www.seisco.com/pages/challenge.html

[Bob1000]

You are both right! Instant water heaters must have a certain amount of flow to keep the burner going. However, the flow is dependent on the pressure at the shower head. Using a 40/60 pressure switch, the size of the holes in the shower head allows more water out when the pressure is at 60, than it does when the pressure is at 40.

Actually, adjusting the mixture handles on the shower probably does no good at all to get the burners back on. The shower head is just not letting out enough water to light the burner until the pump comes back on at 40 and brings the pressure up to 45 or 50.

Make sure your pressure regulator has a thermal bybass, then install it on the house line and set it at 50 PSI. Then set you pressure switch as close as you can to 60/80. This is not good for the pump but, will give you a constant 50 for the house. If the shower head is not letting out enough water at 50 PSI, you need to open it up.

I assume you have already removed the little "water saver" washer from the shower connection line. If not, do so, and that may solve your problem. After removing the washer with the small hole, the only way to get more flow is to drill out larger holes in the shower head.

This is what I suggested to do earlir but you did not recommend using PR and talked about the creep and friction losses, but YES I am convinced by this idea as I got already a nice PR of good make and it has a thermal bypass too although I do not have any central heating system in the house to need that thermal bypass, or what is it for?

Will fix the PR and adjust the system and tell you all the result
Thank you all

[Mikey]

If you could find a way to put a storage tank about 120' above the house, your problem would be solved.

[valveman]

The high pressure from the "creep" of the PRV will give you a shot of high pressure the instant you turn on the faucet but, then it will go away. Set the PRV to 60 with the pressure switch set at 60/80, and that will help some with the friction loss. The pressure difference from friction loss of the PRV will still be less than from the pump cycling directly into the house at 60/80. Without a CSV, it is about the best you can do. Have you removed the "water saver" washer from the shower head?

The thermal bypass will let water pressure go backwards through the PRV. When the water heater heats up the water it will expand and needs some place to go. The thermal bypass will let it go back through the PRV to the pressure tank, so the pipes don't blow up.

[Bob1000]

The high pressure from the "creep" of the PRV will give you a shot of high pressure the instant you turn on the faucet but, then it will go away. Set the PRV to 60 with the pressure switch set at 60/80, and that will help some with the friction loss. The pressure difference from friction loss of the PRV will still be less than from the pump cycling directly into the house at 60/80. Without a CSV, it is about the best you can do. Have you removed the "water saver" washer from the shower head?

The thermal bypass will let water pressure go backwards through the PRV. When the water heater heats up the water it will expand and needs some place to go. The thermal bypass will let it go back through the PRV to the pressure tank, so the pipes don't blow up.

The shower head is an expensive Grohie ( German make) and the nozels are protruding rubber nozils for ease of scale cleaning and smooth water jets , it is a very nice adjustable modes head for massage too , there is NO water saver washer there !

with the present pump ( the 1HP self priming ) it can not give a dead head of 80PSI without a good 25 PSI from the city pressure , right now it is ok but in the peak summer the pump would not be able to shut itself off , so I would fix the new 2HP twin impillers that I bought - or will give the market here another search for a good Jet Pump that can give that pressure on its own

I am thinking of something that might give the same effect of CSV but it would be of course much more expensive than a proper CSV!
What do you think about fixing a PRV to the outlet of the pump and set it to say 70 PSI then before it T - fix a bypass 1/2" pipe parallel to the outlet piping with a bypass pressure relief valve set to say 10 PSI more than the cut out pressure of the pressure switch then T back into the ain line again just before the T of the pressure tank and presure switch group ? , so if we use 50/75 setting , we set it to 85 PSI
I think this system would keep the pump running continous during the shower and avoid harmful cycling
Thank you very much for your help

[valveman]

You are on the right track, and very close to making a Cycle Stop Valve equivalent. You really only need to by-pass a certain amount of flow around your pressure reducing valve. A tee before and after the PRV, connected by a 1/4" pipe which includes a 1/4" ball valve is all you need. The pressure relief valve you described will not work.

Set the PRV to 70 PSI, with the pressure switch set at 55/75. Then crack open the 1/4" ball valve to allow about 1 GPM to by-pass the regulator. This will work exactly like a Cycle Stop Valve. You can also just drill a hole through the body of the PRV, usually in the bridge wall below the valve closure. In this way you do not need the bypass tee connections and ball valve.

This has been tried for decades and is also the way the very first Cycle Stop Valves were built. Many companies are now making valves this way to try and compete with the Cycle Stop Valve.

The problem arises from the small size of the bypass. A drilled hole would need to be no larger than 1/16 of an inch in size. The 1/4" ball valve would also need to be barely cracked open to make a 1/16" opening. The small 1/16" hole is very similar to the size of a single hole in the shower head. Just as the holes in your shower head will usually become smaller and then clog from hard water deposits building up, so will this 1/16" size hole. Water coming through this 1/16" opening is responsible for the cooling of the pump. When this 1/16" hole becomes clogged, the pump will overheat and be destroyed.

Making the hole larger is how many companies try to keep it from clogging up. The larger the hole, the higher the minimum flow through the valve. When the minimum flow through this hole is greater than the amount of water being used, the pump will cycle on and off. In other words, if you make the hole large enough to allow 3 GPM minimum flow, anytime you are using a 2.5 GPM shower, the pump will cycle on and off, and the shower will see the pressure change from 55 to 75, which is what caused the problem with the instant water heater to start with.

The Cycle Stop Valve solves this problem by not using a drilled hole or bypass line. The Cycle Stop Valve uses a half moon notch across the valve seat. The size, shape, and placement of this notch has been engineered to eliminate clogging, velocity wear, noise, and valve seat chatter. Anytime the valve opens, the half moon notch is flushed of debris and hard water deposits, which eliminates any chance of burning up the pump. This simple change of design is what makes the Cycle Stop Valve dependable compared to other types of valves.

I know freight and customs is the biggest issue but, we send Cycle Stop Valves all over the world. We have customers in the Phillippines, New Zealand, Australia, England, South America, Canada, Virgin Islands, Trinidad, and many other places. You can try to make your own, or you can get the benefit of our many years of experience by using a REAL Cycle Stop Valve.

[Bob1000]

You are on the right track, and very close to making a Cycle Stop Valve equivalent. You really only need to by-pass a certain amount of flow around your pressure reducing valve. A tee before and after the PRV, connected by a 1/4" pipe which includes a 1/4" ball valve is all you need. The pressure relief valve you described will not work.

Set the PRV to 70 PSI, with the pressure switch set at 55/75. Then crack open the 1/4" ball valve to allow about 1 GPM to by-pass the regulator. This will work exactly like a Cycle Stop Valve. You can also just drill a hole through the body of the PRV, usually in the bridge wall below the valve closure. In this way you do not need the bypass tee connections and ball valve.

This has been tried for decades and is also the way the very first Cycle Stop Valves were built. Many companies are now making valves this way to try and compete with the Cycle Stop Valve.

The problem arises from the small size of the bypass. A drilled hole would need to be no larger than 1/16 of an inch in size. The 1/4" ball valve would also need to be barely cracked open to make a 1/16" opening. The small 1/16" hole is very similar to the size of a single hole in the shower head. Just as the holes in your shower head will usually become smaller and then clog from hard water deposits building up, so will this 1/16" size hole. Water coming through this 1/16" opening is responsible for the cooling of the pump. When this 1/16" hole becomes clogged, the pump will overheat and be destroyed.

Making the hole larger is how many companies try to keep it from clogging up. The larger the hole, the higher the minimum flow through the valve. When the minimum flow through this hole is greater than the amount of water being used, the pump will cycle on and off. In other words, if you make the hole large enough to allow 3 GPM minimum flow, anytime you are using a 2.5 GPM shower, the pump will cycle on and off, and the shower will see the pressure change from 55 to 75, which is what caused the problem with the instant water heater to start with.

The Cycle Stop Valve solves this problem by not using a drilled hole or bypass line. The Cycle Stop Valve uses a half moon notch across the valve seat. The size, shape, and placement of this notch has been engineered to eliminate clogging, velocity wear, noise, and valve seat chatter. Anytime the valve opens, the half moon notch is flushed of debris and hard water deposits, which eliminates any chance of burning up the pump. This simple change of design is what makes the Cycle Stop Valve dependable compared to other types of valves.

I know freight and customs is the biggest issue but, we send Cycle Stop Valves all over the world. We have customers in the Phillippines, New Zealand, Australia, England, South America, Canada, Virgin Islands, Trinidad, and many other places. You can try to make your own, or you can get the benefit of our many years of experience by using a REAL Cycle Stop Valve.

Thank you very much Valveman , you made me really very very interested in the issue of stopping pump cycling and I believe that your CSV is really an excellent invention the way your discribed . I am very glad that I could think of an alternative near to your CSV , all that because of the ideas I have learnet in this forum which I am really grateful for.
However I do not really understand why a bypass valve would not work even better than the 1/4" ball valve?
I forget to tell you that I was going to set it to the dead head pressure of the pump which is the max pressure the pump would be able to generate .
It might be even more useful because at that pressure it would suddenl open and fills the pressure tank in very short time in stead of the pump struggle to fill the tank in the case of any 1gpm valve
What do you think?