Low Water Pressure

[Pib]

I would fix any leak. 

 

However, the way you made the leak sound so tiny it don't sound big enough to cause you pump to turn on every minute...maybe you have another leak somewhere casing that.

[aoneseller]

Yea. Actually I just found one; broken hose that feed our toilet. I will change it tomorrow.

[lopburi3]

Other place to check is inside toilet to make sure there is no overflow (water level low enough and valve not leaking) but suspect you checked that and found the leaking hose.

[aoneseller]

I changed the toilet hose, pump is OK now. I might redo the check valve later, anyway my meter doesn't move if all water outlet closed.

[Pib]

Sometimes it just hard to even impossible to get a leak-free seal between a PVC connector and a metal connector like on the check valve due to differences in thread specs....and it don't matter how much Teflon tape you use.  Teflon tape simple can't provide a leak proof seal with certain thread difference between the two connectors.    Actually Teflon tape is meant to seal "metal-to-metal" connections....while it's widely used on PVC connections also it's not the best thing to use.  Instead, a "non-hardening sealant" should be used like plumber's putty which is practically impossible to find in a Thai hardware store as Teflon tape rules!!!

 

I've had times where I had tiny leaks even after several retries....using less Teflon tape....using more Teflon tape.  Normally, you should wrap a connector 2 or 3 times when using Teflon tape....more than 3 rarely helps...can actually cause hairline cracking on PVC connectors when tightened too much. 

 

But what will provide a leak-proof seal each and every time is using plumber's putty (a.k.a., non-hardening sealant).   As mentioned finding something called plumber's putty in a Thai hardware store is hard....I know I've never found any and I've looked in HomePro, Thai Watsadu, and Global hardware stores and small mom-and-pop stores....I've never found any.

 

However, I have found non-hardening sealant in a tube which works absolutely great. No, I'm not talking silicone in a tube which dries too hard.   Below is what I've been using on the type of connection, like PVC-to-metal screw together connections or even PVC-to-PVC screw together connections....leak tight each and every time.  Be sure to wait about 15 minutes before applying water pressure.  I find it in HomePro stores...probably in Global and Thai Watsadu stores also....costs a little over Bt100 for  tube.   When you read the description you see it's a silicone based sealant but it does not dry as hard as regular silicone in a tube like you might use to seal around windows.  It's more like a plumber's putty.

 

http://www.allaboutwaterproof.com/anti fungus sealant-colosil

[aoneseller]

Thanks for the info. I was thinking to apply solvent cement on the PVC side and Teflon the check valve thread. But your recommendation sounds better.

And do I need to use Teflon tape with the non-hardening sealant?

[wayned]

7 hours ago, Pib said:

Sometimes it just hard to even impossible to get a leak-free seal between a PVC connector and a metal connector like on the check valve due to differences in thread specs....and it don't matter how much Teflon tape you use.  Teflon tape simple can't provide a leak proof seal with certain thread difference between the two connectors.    Actually Teflon tape is meant to seal "metal-to-metal" connections....while it's widely used on PVC connections also it's not the best thing to use.  Instead, a "non-hardening sealant" should be used like plumber's putty which is practically impossible to find in a Thai hardware store as Teflon tape rules!!!

 

I've had times where I had tiny leaks even after several retries....using less Teflon tape....using more Teflon tape.  Normally, you should wrap a connector 2 or 3 times when using Teflon tape....more than 3 rarely helps...can actually cause hairline cracking on PVC connectors when tightened too much. 

 

But what will provide a leak-proof seal each and every time is using plumber's putty (a.k.a., non-hardening sealant).   As mentioned finding something called plumber's putty in a Thai hardware store is hard....I know I've never found any and I've looked in HomePro, Thai Watsadu, and Global hardware stores and small mom-and-pop stores....I've never found any.

 

However, I have found non-hardening sealant in a tube which works absolutely great. No, I'm not talking silicone in a tube which dries too hard.   Below is what I've been using on the type of connection, like PVC-to-metal screw together connections or even PVC-to-PVC screw together connections....leak tight each and every time.  Be sure to wait about 15 minutes before applying water pressure.  I find it in HomePro stores...probably in Global and Thai Watsadu stores also....costs a little over Bt100 for  tube.   When you read the description you see it's a silicone based sealant but it does not dry as hard as regular silicone in a tube like you might use to seal around windows.  It's more like a plumber's putty.

 

http://www.allaboutwaterproof.com/anti fungus sealant-colosil

I use the red RTV, form a gasket, that can be found in automotive supply stores.  Also if both fittings have a flange on then I put a "O" ring on the male side so if it is tightened  flange to flange the "O" ring provides and additional seal..

[lopburi3]

The other alternative is to use metal to metal - all the PVC screw connections I have used have metal inserts inside the plastic pipe and work fine.  Suspect costs a bit more but for normal home use not that much.  The tape will then work fine and is what it is designed for.

[Pib]

Thanks for the info. I was thinking to apply solvent cement on the PVC side and Teflon the check valve thread. But your recommendation sounds better.
And do I need to use Teflon tape with the non-hardening sealant?

Use the sealant only....do not use sealant and Teflon tape on the same connection...sealant only.

[aoneseller]

OK. Now about my pump.Mitsubishi EP155 constant pressure. In the morning works fine, however after 7 pm keeps running non-stop even if I turn off the outlet valve too. I already adjusted the pressure switch but I don't really want to touch it because the Phillips screw head so soft I might damage it. I also drained the pump but it was in the morning. Can be because of the main soi line water pressure increase in the evening? Or should I get a pressure gauge and check the house water pressure and keep adjusting the switch like Pib said earlier an other forum? But as I said that screw is soft. Thanks once again for your answers, first time I have water pump.

[Pib]

Sounds like it might be running dry....no water to suck....low, low soi water line pressure.  At around 7pm is the right time for water pressure to go down as everyone is home from work and school washing their bodies/using more water.    HOWEVER, BUT, just a few days ago you said you had installed a storage tank setup....so, is there water in the tank to feed the pump or is the tank running dry...is it filling up.

 

DO NOT mess with the pressure switch unless you know what you are doing and have a pressure gauge!

[aoneseller]

No, water tank is full. Anyway, I keep observing for a few days more. 

[lopburi3]

Could be the check valve - during day mains pressure enough to prevent backflow to soi but at night when city water pressure is low your pump is trying to provide them pressure.  I am a firm believer in not using such valve myself and always use cut off - I can then always have good water pressure from my pump and if power fails I can bypass and turn that valve on to obtain city water pressure.

[wayned]

5 minutes ago, lopburi3 said:

Could be the check valve - during day mains pressure enough to prevent backflow to soi but at night when city water pressure is low your pump is trying to provide them pressure.  I am a firm believer in not using such valve myself and always use cut off - I can then always have good water pressure from my pump and if power fails I can bypass and turn that valve on to obtain city water pressure.

Yeap!  Did away with the check valves long ago as the crap in the water supply caused them to stick open.  I replaced them with on/off valves so when the electric goes off, or we have a brownout (the pump motors don't like low voltage), I just go out and turn a couple of valves to get the water from the local supply which is normally a trickle as I'm the last house on the line.

[aoneseller]

I still don't get it. My water tank full. I have a valve after the pump close by. If I turn off that valve during day the pump stops. In the evening if I turn off the valve the pump doesnt stop. Anyway I unplug the pump most of the time, only time I use when we take shower upstairs.

[bankruatsteve]

4 minutes ago, aoneseller said:

I still don't get it. My water tank full. I have a valve after the pump close by. If I turn off that valve during day the pump stops. In the evening if I turn off the valve the pump doesnt stop. Anyway I unplug the pump most of the time, only time I use when we take shower upstairs.

If your pump runs non-stop and the tank stays at the same level (filling while the pump runs?) then it is obviously going in circles.  That is usually from a check valve stuck open or a normal valve that needs closing at the point where the pump output connects to the mains.

[aoneseller]

It is not possible that its going in circles. As I said before I have a valve after the pump outlet. If I close that valve  in the daytime the pump stops, during evening the pump keeps running.

However, I observed in the last few days I have a slightly voltage drops in the evenings. Same time when the pump keeps running. During day house has 220 V, in the evening it drops to 210V. Could be this messing with the pump?

[wayned]

No, the voltage drop to 210V isn't the problem, the motor should run fine.  Low voltage could cause the pump motor to run slow not letting it to achieve cutoff pressure, but not just 10vac. If the voltage here gets down to about 160vac the motor on my Mitsubishi won't start and the thermal overload cuts in.  Where did you measure the voltage?  You need to measure it directly at the input to the pump.

[Pib]

What I have experienced with my Mitsubishi WP255 pump in the past during voltage brownouts at around 160 to 180 volts and below when the pump kicks-to run to rebuild pressure due to the low voltage it can never reach full speed.  When it can't reach full speed it can't rebuild the pressure high enough to (2.8bar point on my pump) to cut the pump off.  So, the pump continues to run and run until it gets so hot the motor's built-in thermal protection device disconnects.  This thermal protection device is built internally to the motor...you will not see it externally anywhere. 

 

After approx 15 to 30 minutes  to where the pump motor has cooled down enough the thermal protection device automatically reconnects. The pump begins running again...can't reach sufficient speed....after X-minutes overheats again....thermal protection circuit disconnects gain.   As long as the voltage is low this cycle will continue until the pumps flat-out fails electrically or mechanically....and is just stays dead. 

 

210 volts is plenty of voltage for the pump to run properly.  If I remember right these pumps are spec'ed to work -15%, +10% of 220V which would be approx 187 volts to 242 volts.

 

 

[wayned]

My 255 does the same thing, but the bearings are bad and it just won't start at less than 180V, it just overheats.. My wife didn't understand "don't use water when the lights are dim" so I installed a switch in the kitchen and a meter beside it.  When the voltage drops I turn the pump off and go outside and switch to local water, I don't have a check valve installed.  It could be that at night due to improper wiring and increase local use of power, the OP could be getting lower voltage at the pump connection which would cause the pump to run and never cutoff until it overheats, I assume that the Hitachi pumps also have a thermal protection.

[Pib]

I have a panel voltage meter on my house circuit breaker box.  Whenever a brownout/blackout occurs (fortunately for the last fews years there have been few but they still happen a couple times per year) I've told the wife just to go outside and turn off the switch on a wall which provides power to the WP255.  She knows from years past when the brownouts were too frequent how the pump would just run and run until it overheats and stops...and then begins the cycle again.

 

Now, whenever I'm home and a brownout/blackout occurs I just turn off all the individual circuit breakers feeding different parts of my home to include the pump outside as I don't want any of my electronic/electrical equipment trying to continue to work on a lower than normal voltage or experience the surge(s) when the power returns to normal. 

 

I could just cut off the one main breaker vs all the individual breakers but I don't want that one main breaker feeling the entire surge for the entire house at the same instant the power comes on....instead, I just turn each individual circuit back on one after the other which results in small upward steps of current returning to the entire house.

 

Yeap, a panel voltage meter which displays the voltage coming to your home 24/7 comes in very handy.

[aoneseller]

After I got the pump properly wired outside my evening problem gone away. Before I used just an extension from the house. Now its plugged in all the time (in a rainproof box) its got an on/off switch and works when it needs to work automatically.

[carlyai]

I use the red RTV, form a gasket, that can be found in automotive supply stores.  Also if both fittings have a flange on then I put a "O" ring on the male side so if it is tightened  flange to flange the "O" ring provides and additional seal..

Hi@wayned we keep on meeting on different threads.

I have a non return valve between my pool pump and the filter. 2" pipe into a male thread connector into the female NRV. Both sides of the connector NRV leak, like annoying drops every minute or so.
I've removed and re- wound white tape 2 times already and did a no no by spanner tightening the connector, but it still leaks.

Going to try your way.

So I liberally apply the RTV then do up the connector?

Sent from my SM-J700F using Tapatalk

[wayned]

1 hour ago, carlyai said:

So I liberally apply the RTV then do up the connector?

I smear it on liberally, tighten the fitting and wipe off the excess.  I usually let it set up for about 30 - 60 minutes before turning the water back on.  

 

There is also a two part epoxy that is water proof.  It's called "Aqua Putty". I buy it in Home Pro.  I used it when I built my house 18 years ago to seal leak in the output of my water tank and to seal the drain pies under the sink with all intentions of going back and redoing the leaking fittings.  That was 18 years ago and they are still not leaking and I'm not one to fix something that's not broken.

 

If you use it I do not know how easy it would be to undo the fittings as it is an epoxy.

[carlyai]

I smear it on liberally, tighten the fitting and wipe off the excess.  I usually let it set up for about 30 - 60 minutes before turning the water back on.  
 
There is also a two part epoxy that is water proof.  It's called "Aqua Putty". I buy it in Home Pro.  I used it when I built my house 18 years ago to seal leak in the output of my water tank and to seal the drain pies under the sink with all intentions of going back and redoing the leaking fittings.  That was 18 years ago and they are still not leaking and I'm not one to fix something that's not broken.
 
If you use it I do not know how easy it would be to undo the fittings as it is an epoxy.

So....your recommendation is to go with the first option, as I may need to get it to pieces again to replace the non-return valve as I hear they do rust out.

Or have another go with more tape?

Decisions decisions.

Sent from my SM-J700F using Tapatalk

[wayned]

All of the NRVs that I have used have been brass so rust shouldn't be a problem.  The problem that I have had with them is with the "dirty" local water, calcium build-up, eventually keeping them from shutting properly.

 

The problem that you are having is most likely caused by screwing the male plastic fitting into the female brass fitting.  If you can find them, and they are available, I would replace the fitting on the plastic pipe with one the has metal threads:

 

I have used them but never as big as 2". Since both the fitting and the NRV both have shoulders on them you could also try finding an "O" ring that will fit over the male end against the flange so that when you tighten it down it will compress between the two flanges.  I always put them on the 1/2 and 3/4 fittings and faucets but I, again, I have never looked for "O" rings to fit on 2" pipe.  Most likely would have to take the fitting to an auto supply or, better yet, a tractor parts supply place.

[wayned]

If you can't find a transition fitting with male metal threads, I know that you can find them with female metal threads, even the Ma & Pa store in the village has them, you could fit one with female threads and connect the NRV to it using a metal "nipple".  Only tape should be required when fitting metalto metal.

[aoneseller]

As I mentioned before my pump wasn't turning off in the evenings. This problem still occurs sometimes. However, today I discovered something. 

Same thing happened, the

pump was running and then suddenly stopped. I couldn't turn it on, I unplugged, plug again, still was off. Then I checked my watertank, I opened it and the pump was on again and it stopped same like normal. Stopped when it supposed to stop.

I think its because the pressure increases in the watertank causes the extra flow and messes with pressure switch. Because when I opened the water tank i must have released the extra air pressure inside. Also there is a vent hole on the top. I guess I will leave it open now.

[BEVUP]

On 1/20/2018 at 9:09 PM, aoneseller said:

As I mentioned before my pump wasn't turning off in the evenings. This problem still occurs sometimes. However, today I discovered something. 

Same thing happened, the

pump was running and then suddenly stopped. I couldn't turn it on, I unplugged, plug again, still was off. Then I checked my watertank, I opened it and the pump was on again and it stopped same like normal. Stopped when it supposed to stop.

I think its because the pressure increases in the watertank causes the extra flow and messes with pressure switch. Because when I opened the water tank i must have released the extra air pressure inside. Also there is a vent hole on the top. I guess I will leave it open now.

This was very simple from the start

You did not have a pressure cut off switch for the lack of supply water from Moo Baan

This brings me to a question as 2 houses across the road are in the process of putting a pump between the meter & tank

 

?????  WHAT IS THE POINT OF PUTTING IN SUCH PUMP

 

! So lets say you get a certain amount of water (pending time of day ) & it takes like 2-3 hrs to 1/2 fill your typical Moo Baan tank 

 

Is this pump going to cut this time in half ?

 

If the water pressure is just enough to have a trickle into the tank (which may take most the night to refill tank ) will it be enough for the pump or will it no doubt being going on off all night ?

 

 

 

 

[lopburi3]

Besides being illegal, bad neighbor, and a danger?  Pumping directly from mains can draw both groundwater (if any breaks in line) and neighbors wash water if hose in pail and water pressure goes negative.  If there is not enough pressure to get to top of tank they should have underground tanks or a low tank and pump from that to larger tanks.

 

Pump from tank does not require anything but water source - as long as there is water in the source tank the pump will be happy and work fine.  But the source tank should not be air tight - leave that to your pressure tank (if you have one - and highly advise having).