(Another) Water Pump Question (But Unusual)

[HughG]

I've read other posts on water pumps, and my issue seems to be a little different.

My water pump works fine for the garden hose, which is on a separate line from the line running into the house. I turn on the hose, the pump clicks a couple of times and pumps just fine. I can squeeze the hose to restrict the flow, the water stays on and the pump keeps pumping, no problem.

However, when I turn on any tap in the house (with the garden hose off), the pump starts clicking and never stops clicking. It's definitely rapid cycling, because the water pulsates as it comes out of the tap. But ONLY in the house. As I said, the garden hose works just fine, no problem. It's got me mystified.

Any hints as to what may be causing this? It's a Mitsubishi pump, only been used maybe two or three months (but it sat unused for about six months or so before moving into the house).

Thanks in advance.

---- Hugh

[Doodoo]

Maybe that the opening of the house valves are using less water than the hose outside This maybe the reason for the clicking (less water use )

[tamada]

Without specifics of pump type or model, it's not easy to tell what's causing this issue, but If you type "rapid cycling water pump" in Google search, the most common causes are explained.

[HughG]

OK, I'll give that a try. Thanks.

[Potamoi]

Check this thread on AseanNow:
https://aseannow.com/topic/1131119-mits ... e_vignette

Like Tam said it depends on the model whether it has an accumulator with xx psi air pressure in the bladder to regulate the pressure switch or an Air Control. Some have adjustments one can make and other not.

My money is on a small hole or tear in the diaphragm. As for why it is only with the house side and not the garden hose side is odd but it may have something to do with the back pressure involved on the house side given the frictions involved within the pvc and kitchen or toilet plumbing. This might make the issue more apparent on a different pressure range than the hose. Volumes involved in the piping too. The more volume in the plumbing, the more potential for slight 'ballooning' to take place.

[kopkei]

you need to adjust the pressure switch , the best way to do this is if you have those water heaters in bathroom , lower flow , open the water there , your pressure switch from pump will be probably be jumping on and off , tick tack , adjust the pressure switch until the tick tacking stops and you have a steady flow , than check when closing water the pump stops ...if not you also need to adjust the closing , but until now i have never needed to change this before , and now i do not use this kind of pump anymore , only centrifugal pumps ,( grundfos mq45, walrus tq800, and a very cheap good working , 2.250 baht, bonchi wzb-c750, for those who need a cheap good alternative ) which do not have the same pressure switch and do not have this problem ...

[tamada]

The pressure switches on most every water pump are tamper-proof, sealed and are not supposed to be adjusted. My experience (actually the brother-in-laws idea), chasing that solution and you can end up going in circles by adjusting something to "fix" a fault elsewhere.

Depending on the pump type, either excessive back-pressure in the home plumbing, a flooded air bladder, a leaking diaphragm, pin hole leak in the pressure tank or a bad pressure switch.

[gghh]

Maybe that the opening of the house valves are using less water than the hose outside This maybe the reason for the clicking (less water use )

Open 2 or 3 taps in the house at same time to verify

[Khun Paul]

Fixing faults is time consuming problem, first check the pump and ALL COMP{ONENTS and pipeworkin to and out of pump, once stisfied that the pump is working correctly, open yalve to the house and ensure ALL tapsetc are open and watch the water flow, then go to each room with a water outlet and turn them off. Then go back and reopen room by room havinmg someone listen to the pump, if the pump reacts as you described only from one room then the problem is in that room. INVESTIGATE AND DEAl as appropriate.

IONLY HAve Mitsubishi pumps nad occasionally had to change switch and diaphram ( Due to an Ant invasion ) that was in the well pump in the back of the garden, spray every three four months keep the blighters away. Generally never changed anything attached to the pump, but have found that sometimes the pipes attached to the pump air pressure etc are not as tight as they should be.

[glalt]

I made the mistake of buying one of those Hitachi turbine water pumps. It uses one of those nitrogen accumulators and cycles on and off continually. I will never again buy a water pump with out a pressure storage tank. That pump is used for the bathroom in my separate game room so it doesn't get used that often. The pump itself has a water leak in the housing and now needs a new large rubber "O" ring. I think installing a bladder storage tank would eliminate the cycling but decided that it is not worth the work and expense. It's just a poor design.

[kopkei]

The pressure switches on most every water pump are tamper-proof, sealed and are not supposed to be adjusted. My experience (actually the brother-in-laws idea), chasing that solution and you can end up going in circles by adjusting something to "fix" a fault elsewhere.

Depending on the pump type, either excessive back-pressure in the home plumbing, a flooded air bladder, a leaking diaphragm, pin hole leak in the pressure tank or a bad pressure switch.

well i have never had any more problem after adjusting the pressure switch to a fluid water flow , and in case of the OP , a pump of 9 months old ? , easy to open the pressure switch and adjust ,even they are tamper proof? , but you can start ending up in circles by chasing a better solution tam...

[HughG]

Well, there is no model number on the pump or its housing (just what appears to be installation instructions in Thai), so I'm chasing down the paperwork in the hopes that it lists the model number. I'm also going to try the suggestions here and at the links provided and see what happens. Being a novice working with pumps, I'll take it one careful step at a time and report back with the results. Worse that can happen is that it blows up and I need to get a new one. Meanwhile, thanks to one and all for your suggestions. : )

[tamada]

The pressure switches on most every water pump are tamper-proof, sealed and are not supposed to be adjusted. My experience (actually the brother-in-laws idea), chasing that solution and you can end up going in circles by adjusting something to "fix" a fault elsewhere.

Depending on the pump type, either excessive back-pressure in the home plumbing, a flooded air bladder, a leaking diaphragm, pin hole leak in the pressure tank or a bad pressure switch.

well i have never had any more problem after adjusting the pressure switch to a fluid water flow , and in case of the OP , a pump of 9 months old ? , easy to open the pressure switch and adjust ,even they are tamper proof? , but you can start ending up in circles by chasing a better solution tam...

So "Isaan engineering" worked for you. Well done. I was just pointing out that there's no "one-size fits all" solution.

[tamada]

<duplicate>

[tamada]

Well, there is no model number on the pump or its housing (just what appears to be installation instructions in Thai), so I'm chasing down the paperwork in the hopes that it lists the model number. I'm also going to try the suggestions here and at the links provided and see what happens. Being a novice working with pumps, I'll take it one careful step at a time and report back with the results. Worse that can happen is that it blows up and I need to get a new one. Meanwhile, thanks to one and all for your suggestions. : )

Post a picture. That will tell us what type of pump it is (pressure system) and the issues and repairs unique to that type.

[glalt]

Most water pump tanks do not have an air bladder inside. The air inside is gradually absorbed into the water. When that happen the tank becomes waterlogged and the pump will telegraph. Meaning it will cycle on and off every time a tap is opened. Those tanks have a plug that can be removed and the tank drained. Shut off the power and drain the tank. That will give it a new air head and the pump will again function properly. You must drain that tank every couple months. Tanks with an air bladder don't have this problem.

[Khun Paul]

Most water pump tanks do not have an air bladder inside. The air inside is gradually absorbed into the water. When that happen the tank becomes waterlogged and the pump will telegraph. Meaning it will cycle on and off every time a tap is opened. Those tanks have a plug that can be removed and the tank drained. Shut off the power and drain the tank. That will give it a new air head and the pump will again function properly. You must drain that tank every couple months. Tanks with an air bladder don't have this problem.

While that advice may be what your particular pump requires, I have had pumps here working for over 15 years and NEVER DRAINED them using that procedure.Mine are ALL Mitsubishi Pumps, in the course of 22 years changed pressure switch and the octaganal thingy on two`of my four pumps , anything else was once a tank dried out and screwed up the pump running dry. The trick aprt from cleaning out the ants , rubbish etc, is to ensure a good flow of water all the time . Ap[art from that nary a problem. I CONSIDER changing only two of my four pumps in 22 years not too bad, the well one is original 20 years and only once stopped due to a pipe coming pout oif the ground clogging up.

Moral is never BUY cheap pumps, may sound stuffy but pays for itself in the end

[FrazeeDK]

I've had two Mitsubishi pumps since I built the house in 2007. The first one basically fried after pumping dry when a pipe broke. The pumphouse was full of smoke and the pump burning hot.. Oh well, things happen although I wondered why Mitsubishi doesn't put an internal breaker for overheating into the pump...

[HughG]

Well, there is no model number on the pump or its housing (just what appears to be installation instructions in Thai), so I'm chasing down the paperwork in the hopes that it lists the model number. I'm also going to try the suggestions here and at the links provided and see what happens. Being a novice working with pumps, I'll take it one careful step at a time and report back with the results. Worse that can happen is that it blows up and I need to get a new one. Meanwhile, thanks to one and all for your suggestions. : )

Post a picture. That will tell us what type of pump it is (pressure system) and the issues and repairs unique to that type.

Okay. Progress. Found the pump model: Mitsubishi WP-105R. And here's a schematic of the pump setup. All valves were open except #4, which was closed.

I did a test and the pump stopped clicking after I opened FIVE taps in the house.

I did another test, where I opened Valve #4, and, lo and behold, that resulted in normal pressure at the taps in the house and the pump didn't turn on. I take this to mean the external supply line must provide more pressure than the house pump. I'm guessing from this that the house pump is not putting out enough pressure, and it should be increased. (Hoping that logic holds, but certainly could use advice.) I also realized that the house pump could (and probably should) be used as backup only since the external supply provides all the pressure the house needs. I'm also guessing that's likely how it was supposed to be set up from the get-go, so I'm going to leave it set up that way unless I get advised otherwise (as you can see, I really am not very knowledgeable about pump setups).

[Khun Paul]

WP 105 is the smallest pump MITSU DOES< FOR A HOME I would at least have WP 255R TO ACCOMODATE ALL THE NEEDs< kitchen, toilets and showers etc :-

Y well p[ump is 105, but then all it feeds is one tank at its own speed , the rest of the tanks are filled up by gravity .