Electrical Water Pump Fuse Keeps Blowing....

Hi everyone, hopefully someone will be able to help. I have a fuse which keeps blowing. My flat is electric only. Within a storage cupboard in my hallway, I have the water tank, boiler, pump, the pump is wired to a fuse socket on the wall, which up until now has housed a 5 amp fuse. My fuse box (Wylex) states that total power is not to exceed 100 amps. It sometimes takes 1 or 2 hours to blow or sometimes 1 or 2 weeks, which would suggest it could be a load on the circuit issue (if i'm making an educated guess?). I must also mention that we once put a 13 amp fuse in place of a blown one which never actually blew, however my other half was adamant she could smell burning. We also often hear a feint buzzing sound before the pump kicks in to action. 

With no gas, we use electric wall heaters (got rid of the old storage ones!). IF we were to have everything on, including the heaters at full blast, we would be using around 4000 watts at any one time.

Can someone please guide me to the reason why the damn fuse keeps blowing. Is the fuse i'm using too low (the water pump has a label on which states 5 amp and a 5 amp was being used when we moved in). Other than moving out, what are my options to fix this?

Happy to supply pictures if it would help. 

Thanks in advance,

Matt

Explain what the water pump is?

you don't appear to have central heating, so it's not a circulating pump for that.

Is is a pump for water out of a well?  a shower pump or what?

If the pump is drawing more current than it says it should, then it's either under too much load, or it's faulty.

any competent electrician could measure the current it is actually drawing.

Hi, sorry for my lack of details in original post. I don't believe it pumps water out as draining water away has never triggered any use of the pump. It is used when we use any hot water (including the shower) or the toilet refills

The pump is called a 'Monsoon N3.0 Bar Twin'. The wattage input is 860, Amp 3.7 and states a 5 amp fuse should be used. 

There could be an electrical fault within the pump ...like a short cicuit that only happens now & again.    

Does it blow after a period of constant use ?

Or the pump may be struggling to turn due to , perhaps a build up of sludge etc. 

Is it the sort of pump that has a large screw which, when removed,  lets you turn the rotor by hand.?

Just going to glooble your pump.

Ok so a period of constant use doesn't blow the fuse. However if a lot of appliances (I. E. Heeaters) are in use then it does blow.

When the pump works, it pumps fine so not sure if there is any sort of build up or whether I'd be happy to tamper with it not being a plumber.

Going back to my original post, do you not find it odd that it never blew when I used a 13 amp fuse?

Would any pictures of the pump help?

Cheers

Matt

It's one of those shower boost pumps Deke,,, although it seems to be on the main hot and cold feed to the whole of the bathroom....

You should not use it with a 13A fuse,,,, it's not designed for that level of current protection and could become dangerous if it is using too much current.

The 3A fuse is only doing it's job,, it sounds like you have some sort of problem..

You say it blows when the heaters are on???? do you have any way to measure voltage?

It tends to blow when all the heaters are on.....which isn't ideal going into December in Scotland but we don't usually have them all going at once as the place we have isn't huge. In case it helps, we have 4 heaters, a 1200; 1000; 800 & 600 watt.

Ok no more 13 amp fuses!

No way to measure voltage I'm afraid

It sounds like the FCU that feeds the pump also feeds some heaters then.

You are probably best getting an electrician to investigate and take some proper current measurements to see what is fed from this FCU and see what remedial work is needed to make the situation better

So,,, without being able to measure voltage it might be difficult...... I suspect that you might need an electrician anyway

If you have your lights (regular filament lamps) on and you turn the heating on,, do the lamps dim?

Yes your right. The heaters are simply plugged into a wall socket....maybe this is the answer???

Will arrange an electrician in any case as looking to sell up and can't do so with electrical faults

Matt

No the lights don't dim when the heaters are on although all the lights are LED so low wattage. That said I do have 1 bulb in the bathroom which has been turning itself off randomly (normal halogen type, not LED) so could this be related?

As I mentioned before, I say heaters but they are all just plugged into sockets

If the heaters are just plugged into a wall socket, and they work when the pump switch is turned off, then they won't be contributing to the problem.

I still suspect there is something wrong with the pump and it's drawing more current than it should.

If you are looking to sell, it's probably best to get an EICR (electrical installation condition report) done and have any remedial work that it suggests done, then there can be no issues about the wiring.

Just picking up on what has been said above .......  if you switch this spur unit OFF  do those heaters you mention still work?

Yes the heaters continue to work fine even if the power to the pump/spur unit is cut

Matt,,

I'm wondering if you have a very loose connection somewhere which is giving you a higher than normal volt drop when the heaters are on.....

with a lower voltage fixed loads will draw more current - hence the blowing fuse

this could be seen with regular light bulbs,,, LED's are very voltage tolerant

Nozspark, sounds quite possible. Would having a EICR as mentioned above pick this up?

I'm not convinced the pump is the problem here...

It should pick up any problems with the electrical installation on your side of the electric meter. It would be a good thing to have as the condition of the electrics could be used by a prospective purchaser as a bargaining chip against the price of the property.

You say that you've got a flat... which floor are you on? Where is your electric meter?

OK, sounds like an EICR is a good thing to have regardless of whether its a legal requirement of selling or not if only to check for any faults.

Yes we have a flat. We are ground floor. It's really quite a small, 1 bedroom (hence moving). The 'digital' meter is accessible in my hallway.

Just to be clear about some basics.  Electricity always generates heat when traveling through a circuit. More current equals more heat. Every piece of electric cable or flex can only carry so much electric current before it starts to melt. Fuses are used to prevent cables being overloaded and damaged due to the heat while the circuit is running. A normal working appliance will not suddenly start consuming more electricity. Faulty appliances can start drawing more current along the cables. If a fuse has blown then either a fault on the circuit (damage cable) or a faulty appliance has started consuming more power than it was designed to work with. This can result in dangerous levels of heat so fuses must disconnect the power before serious damage, shock, fire or fatality occur. Putting a larger fuse in place of the correctly rated fuse is a potentially dangerous practice. If the pump is the only thing supplied by that fuse then the pump is the most likely candidate for the cause of the problem.

Doc H.

NozSpark said:

I'm wondering if you have a very loose connection somewhere which is giving you a higher than normal volt drop when the heaters are on.....

with a lower voltage fixed loads will draw more current - hence the blowing fuse

Click to expand...

I think if the voltage drop started to get 860W pumps blowing 5A fuses regularly you would notice a lot more things going wrong.

Sounds like the pump is faulty, but it would need looking at to confirm.