The " Finger Test " for circulating pumps

[Agile]

The finger test is a simple way to find out if the pump is working properly without any special test equipment apart from the finger!

The pump head is removed but left wired up to the supply. At this point its important that an earth wire is connected to the pump and ideally it should be tested for continuity from pump body to earth.

The pump head is placed with the impeller upwards on a flat and firm surface.

Hold the pump body firmly with the left hand and switch on the power. The impeller should spin! Use the right index finger ( 2 ) to press down on the left hand side of the impeller which should be moving away from the end of the finger. By pressing down on the outside of the impeller it should be quite difficult to stop it moving. You will probably be able to stop the pump starting with the finger but again only by applying considerable pressure.

If the pump is spinning but can easily be stopped then its quite possible that the capacitor has lost some of its value and this can be measured to see how the value compares with the marked value which is often about 2.6 µF

Tony

 

[Homesafe]

valuable info mr.T but i think that would be better given in the CC.

 

[slup]

What does being an RGI have to do with checking if a pump is working?

 

[diy]

Tony

rather than go through all that would you not simply just test the capacitor!

 

[Homesafe]

What does being an RGI have to do with checking if a pump is working?

we just work with them all the time thats all nothing more

 

[slup]

But if you put it in CC then the only people who would have been able to read Agile's tip would be those people who work with them all the time.

If he was explaining how to test a gas valve, then I could understand why that should be in CC - but a pump?

 

[Homesafe]

I was asking about non gas related issues on here and was informed it would be better in CC,,,

so i'm just returning the good advice

if people started to play with pumps and live parts they might start to get the funny idea that it's easy to work with other parts of heating systems,,

and then who's to blame

 

[ub7rm]

and then who's to blame

Themselves?! Only a fool takes an internet forum as gospel.

 

[Agile]

I was asking about non gas related issues on here and was informed it would be better in CC,,,

Its always better for an RGI to ask for help in the CC so that it does not give the public the impression that RGIs dont know what they are doing.

Testing the pump is something some of the more adventurous DIYers would like to be able to do. Knowing that they had actually done that would enable us to give better advice.

There are other reasons why a pump may be running slow or weakly than a just the capacitor. In any case few DIYers have a capacitance meter.

Tony

 

[mattylad]

And pumps are not always used inside boilers.

Us DIY'rs can often find all sorts of uses for them & want to test 2nd hand pumps for this.

So i'ts good advice Agile - Ta.

Although, is the "finger" at any risk at all?

 

[ChrisR]

Tony - add it to the FAQs??

 

[bradleybear]

I have found it much easier and a lot less bloody if you remove the vent cap/screw from the front of the pump, and gently putting a screwdriver into the hole, testing the resistance of the impeller against the screwdriver, i.e. can you stop the impellor easily when running.
You can also try and spin the impeller with a screwdriver when in situe to see how free it is. Using a finger seems a bit crude, how about a carrot instead?????????

 

[ddk]

the easiest way by far is to remove the vent screw and inserting a screwdriver to see how easy it is to stop the pump running. if you have gone to the bother of draining/bunging the system to remove the pump you might aswell just replace it while youre there! if the pump was knackered then youve solved the problem, if not youve replaced a working pump with another working pump and you have lost nothing!

 

[mogget]

if you have gone to the bother of draining/bunging the system to remove the pump you might aswell just replace it while youre there! if the pump was knackered then youve solved the problem, if not youve replaced a working pump with another working pump and you have lost nothing!

Not if you're a diyer and could have avoided spending out on a new pump!

Of course if either you or someone else is paying for your time then it's probably worth just changing it for a new one.

 

[seco services]

if people started to play with pumps and live parts they might start to get the funny idea that it's easy to work with other parts of heating systems,,

don't tell me your one of these that insists and advises everyone that
"you need to be corgi to do that"