Demand water pump problem

[hhfarang]

I have a Mitsubishi 305 demand pump for the house water needs. It started running for (apparently no reason). I heard it so I went around the house to see if any taps were open and they were not. I went outside and the pump was spewing water around a black plastic screw-in mounted just above the Mitsu ID plate on the front of the pump. I reached down to tighten it and when I did it blew breaking the plastic head off the screw-in mount. I assume this is some kind of over pressure protection. I took one off another pump and screwed it in and when I plugged the pump in the same thing happened.

My question is: Has anyone seen this before and know how to fix it or what is wrong with the pump? Can it be fixed or is a new pump needed (4 years old)? Can anyone recommend someone to take a look at it to find and fix the problem?

Thanks in advance!

[STEVE G]

Obviously this is a bit of guess-work on my behalf, but I think these types of pumps have a diaphragm that will cause the problem that you have there if it starts to leak inside the pump.
If the pump is leaking pressure inside it will run every so often to compensate and on my pump (I don’t remember the make) the plastic cap is just a cover that isn’t there to withstand any pressure, so the water will come out of there.
I would have thought that a hardware shop that supplies Mitsubishi pumps would be able to get it repaired, but if it’s had heavy use for four years it might not be worth it.

[hhfarang]

Thanks Steve,

It was more of a hard plastic screw with a large head for hand tightening than a diaphragm and the pressure built to the point of blowing the head off the screw. Most of the Thai hardware shops I know are closed on Sunday so that leaves me HomePro which I haven't found very useful so far in repairs. Anything I've taken to them for repair had to be shipped to BKK for a month and sometimes it still came back broken.

This is my main water pump so it is somewhat of an emergency. Trust me, none of you want to see me walking around downtown without my morning shower!

You may be right about just replacing it but I am a die hard about not throwing away anything useful (I recycle religiously) so I would like someone to take a look first and see if it is a minor repair.

Let me rephrase my question:

Can anyone give me the number of a good plumber (or pump repair person or expert) that I may get out to my house post haste?

Thanks again!

[crazy88]

Call me 0847177205 .I may be able to help .

Crazy 88

[Nereus]

Let me rephrase my question:

Can anyone give me the number of a good plumber (or pump repair person or expert) that I may get out to my house post haste?
Thanks again!

You could try K . Sang, hp 081 991 2677 ---not called him for some time, so do not know if he is still available. Or, K. Kai, hp 081 190 1927 (good english), should be able to put you on to someone.

Most of those "shallow well" pumps are of the centrifugal type and do not develop enough pressure to require a "relief" valve. They have a pressure switch which could be either faulty, or the orifice blocked up. The switch is usually a sealed plastic canister type with a couple of wires going to it. Some of the smaller type do use a diaphragm and will have a relief valve, in which case it still points to a faulty pressure switch. Not familiar with Mitsubishi, sorry.

[hhfarang]

After running around town I found (the last from any place open on Sunday I think) the plastic replacement part and I called "crazy88" and got some good advice about what may be causing the problem and how to fix it.

Thanks very much '88!

Thanks for the other answers and numbers as well.

I think I'll go have that shower now!

[crazy88]

sorry that was supposed to be a pm .

[nevets]

my pump runs on sometimes ( does not turn off) , this is do to the pressure switch contacts welding together , and need a cleen ( turn off at main supply to pump first ) this done pump control is ok again. To stop any over pressure in the system an inline pressure relief valve should be fitted if the pump does not have one on its own bodywork. This may help someone if they have the same symtems.

[Guess]

I have had a request for information regarding filters that, hopefully SJ or someone can answer.

The scenario is:

There is a well positioned about 50 metres from the house. Water is pumped up from anywhere between 15 & 20 feet below ground level. The water here in Bang Saphan is particularly silted moat of the year.

Th filter gets blocked quickly and the water then by passes the filter and enters the domestic water system. The owner has been told he needs a paper filter but these cannot be bought here.

Can anybody suggest where one can be got in HH and/or is there a better alternative we should be considering.

The house owners has just come out of hospital and is unable to regularly clean the filter anymore.

[Nereus]

I have had a request for information regarding filters that, hopefully SJ or someone can answer.
The scenario is:
There is a well positioned about 50 metres from the house. Water is pumped up from anywhere between 15 & 20 feet below ground level. The water here in Bang Saphan is particularly silted moat of the year.

Th filter gets blocked quickly and the water then by passes the filter and enters the domestic water system. The owner has been told he needs a paper filter but these cannot be bought here.

Can anybody suggest where one can be got in HH and/or is there a better alternative we should be considering.

The house owners has just come out of hospital and is unable to regularly clean the filter anymore.

If the water is as contaminated as you are saying, then trying to clean it with any type of filter is not the best option.
The well pump should be feeding into a settling tank of at least 1000 litres, preferably more, depending on the size of the demand in the house.

You will then need another small pump / pressure unit to feed the house, and put the filter into that section of the system. The tank should be set up with a float valve from the well pump to keep it topped up, and the house pump needs to have its suction well clear of the bottom of it. Also need a means of draining / flushing the tank from time to time, fitted into the lowest point of the tank.

In some places it is a government requirement to have their supply set up in this manner, and you would be surprised just how much silt there is in what appears to be "clean" water.

[Guess]

Thanks for pointing me back on track. I must be going blind.

If the water is as contaminated as you are saying, then trying to clean it with any type of filter is not the best option.
The well pump should be feeding into a settling tank of at least 1000 litres, preferably more, depending on the size of the demand in the house.

OK so well to settling tank which I resume should be at ground level. Blue plastic OK?

You will then need another small pump / pressure unit to feed the house, and put the filter into that section of the system. The tank should be set up with a float valve from the well pump to keep it topped up, and the house pump needs to have its suction well clear of the bottom of it. Also need a means of draining / flushing the tank from time to time, fitted into the lowest point of the tank.

At the moment there is a filter then a pump which takes the water to a 1.6 ton tank on the second floor. Adequate for the size of house I reckon. He has said that the pump keeps running when the well is empty. I told him that should not happen and he eith has the wrong kind of pump or the one he has is F*&@%ed.

In some places it is a government requirement to have their supply set up in this manner, and you would be surprised just how much silt there is in what appears to be "clean" water.

Yes, the water in my house appears clear when you run it but we still get tell tale stains in the bog and the hand basin.

I don't think the government have ever heard of Bang Saphan. We have a local tessabahn who collect money from house and business owners and put up the odd sign here and there stating the obvious. They also put in well camouflaged speed bumps with no warning at all.

[Nereus]

Guess, I have to answer you as you voted for my photo, thks!

It sounds as though the whole set up needs a rehash. Is it a "well" or a bore hole? Either way it may be the source of most of the trouble. 20 ft is not very deep, but I have no idea what depth the water table would be in your area.
The control for the pump can only be achieved in two ways. One way is with a pressure switch sensing in the discharge pipe side of the pump, and the other way is with a float switch in a tank, or reservoir of some type. With a pressure switch it would need to be in conjunction with a float valve that shuts off when the reservoir is full. (the most common way of doing it)

If the pumping capacity of the pump exceeds the "make up" rate of water in the well, it will aggravate any silt problem, and very soon lead to a fubar pump.

Tanks on second stories worry me, and yes it should be at ground level. Stay away from the blue colour tanks, they are not UV resistant. There are a couple of others, one I think is brown in colour, and also has "non-allergy" written on it in Thai. Also stay away from the shiny stainless steel ones, they are c--p. You mention that the filter is first, but that may be just the way you wrote it. The filter has to be on the discharge side of the pump. If it is on the suction side, then that is why the pump keeps running if the filter becomes blocked because there will not be enough water flow, and therefore pressure, to operate a pressure switch.