MQ3-45 1 HP Pressure Booster Pump

We have a grundfos MQ that pumps water to a cabin via an above ground cistern.Lately it will turn on about every 15 seconds and run for a about 5 seconds regardless of demand. It sounds as though there is air leaking inside the pump. From the crappy manual provided with the pump I thought it would be the check valve so I tried to get to it….I have removed the pressure tank and I am assuming the check valve is directly behind it but I have no idea how to remove it. Am I at the right area and if so how do I remove it? Or can someone suggest another solution. Thanks.
Experienced gardeners share their insights in answering this question :
If it is starting and stopping, it most likely does have some type of leak. The check vavlve is normally installed on the suction side of the pump, and sometimes instead of a check vavlve or in addition to, there is a foot valve. A foot valve is just a check valve (usually with a screen) at the end of the line in the bottom of the cistern. If you have much suction lift, and the check valve leaks (or any leak in the suction piping) then the water will drop back into the cistern. This will also cause the discharge side of the pump system to drop in pressure, causing the pump to restart. You mentioned removeing the pressure tank, that tank keeps the pump from short cycling when you have low demand on the system. If the pump is higher than the cistern, and you don’t see a check valve between cistern and pump then you most likely have a foot vavle in the cistern. Hopefully it’s accessable by removing the pipe.

How to Identify and Fix Common Gardening Problems ?

We provide a variety of viewpoints on how to identify and fix common gardening problems. Our sources include academic articles, blog posts, and personal essays from experienced gardeners :

Leaking from your booster pump reduces its effectiveness and can result in more serious problems if not addressed. Leaks can be caused by issues such as broken valves, worn or cracked seals and the water pressure being too high.
The water pump contains several seals and gaskets that keep coolant enclosed and secure as it flows throughout the engine. As these seals and gaskets age, they will become worn, cracked, and dried out. Once this occurs, the coolant can leak from the water pump.
Answer: The air in the system leads to noise. The entire system must be inspected and bled. The pumps may be oversized for the system in question.
Pump seals need lubrication around the shaft to prevent friction and heat. When a pump is run dry, it can quickly result in heat cracks or blisters, and melted or burned seals. These damaged pump seals leak fluid due to pressure, and they can even shatter if the right conditions are met.
A suction side air leak shows itself most commonly by bubbles and splashing and frothing in the pump basket This indicates your pump is not getting the water it needs to function smoothly but, instead, air is getting into the system and starving or semi-starving the pump.
You should unclog the weep hole. But a clogged or leaking weep hole means that the water pump has bad seals. It`s better to just replace the entire water pump assembly once you find a clogged weep hole to avoid further issues.
Without a correctly running water pump, your engine will overheat in the summer or freeze in the winter. This can not only cause damage to the gaskets, cylinder heads and pistons, it often results in total engine failure.
Grundfos pumps, on the other hand, typically last 15-20 years before needing a replacement or repair.
The Grundfos pump has 3 control modes (proportional pressure, constant pressure and constant curve). Each control mode has 4 settings to choose from. The user interface has 1 push button, one red/green LED and 4 yellow LEDs. When you switch on the pump, it runs with the factory pre-setting or the last setting.
Most seal manufacturers say that operation of the seal at one of these limits will result in a minimum life span of two years; three years with some seal types such as those specified in Standard API 682.
Steel Seal™ will not seal leaks in hoses, seals, water pumps, or extremely large cracks in the head or block resulting in the vehicle not starting. If it does not run Steel Seal cannot work as it relies on temperature.
Dry-running protection for water pumps is one of the most important monitoring functions, as bearings and shaft seal may be damaged if the booster pumps run dry. It is thus always recommended to install dry-running protection on all booster sets.
Dry running your pump causes friction, and this friction is strong enough to heat up the impeller, causing it to melt. ² Even minor melting is severely detrimental to your pump`s performance, potentially causing it to seize up and stop working at all.

Discover Relevant Questions and Answers for Your Specific Issue

the most relevant questions and answers related to your specific issue

Pump leaks from the bottom after running, is this normal?
ANSWER : No . the problem is that the ceramic seal that seals between the fluid and the motor and bearings is leaking ( probably from running dry) or the rubber that holds the carbon seal insert has a crack. Suggest you pull the pump down to fix it otherwise the water/ fluid will get into the bearing of the motor and will cause a major failure

I have a pressure booster pump installed which turns on automatically when we open the tap and turns off by itself when we close the tap, but when power goes and comes back(common in india), the pump will turn on even with no tap opened and does not turn off automatically and goes on running, some kind of airlock problem I think, when we just shut off and on water input several times, it again starts working well
ANSWER : Check to see if the output pipe has water in it when the pump swutches off the pump needs to be primed at all time what we normally find cases like this is the pump is higher than the supply or there is an air pocket on the output where the pressure sensor is

How do i increase the pressure in the in-built pressure tank
ANSWER : Right after the discharge outlet, a non-return valve or check valve is usually installed. Check this one out, maybe it is worn out. You may have to replace it. Do this and get back to me if it does not work out.

Grundfos MQ3-35 hums loudly and does not pump. Alarm light does not go on. Pump seems “happy” but when a tap opens and the pump turns on, there is no boost in pressure and the pump just hums loudly… definitely a different noise from normal operation. Seized? Vapor lock? Any help is greatly appreciated.
ANSWER : Hi, seems like the capacitor gone bad or a seized motor. I just fixed mine cranking the motor manually with the use of a flat head screwdriver. In the back of the motor there is a rubber plug about the size of a dime. Take it off an insert a long flat-head screwdriver and crank the motor clockwise a few turns. Remove the screwdriver and try to operate the pump as usual. Good luck …

Pump keeps blowing house fuse – Grundfos MQ3-35 3/4 HP Pressure Booster Pump
ANSWER : It is likely that the shaft seal in the pump has failed and the water is leaking into the motor. Water and electrics = fuse blowing!!

Grundfos MQ 35
ANSWER : Check the capacitor or the centrifugal switch.

Why does my Grundfos MQ water pump keeping kicking on, even when there is no water demand?
ANSWER : Is it newly installed or has it been working for a while till you noticed it?

Alarm mode prevents pump from kicking in… I have
ANSWER : Check level switch.