Loud thud and lights flicker

[VioletG]

For the past few nights there has been a loud thud in the house. I couldnt tell where it was coming from.

Then tonight it's happened about 5 times and was really loud and co-incided with the lights flickering.

I am assuming it's something electrical. Although at 4am the fire alarms went off. Happened again this afternoon . They are are not wired into the main supply (I'm guessing a co-incidence)

The house is on old 1930s house and the fuse box looks kind of like this

Anyway I can't sleep worrying about it.

 

[VioletG]

I just wanted to add it only seems to happen at night

 

[securespark]

Which lights flickered?

Pull the fuse for 24 hours and see if the banging stops.

If it does, call a spark!

 

[VioletG]

I was sitting in the living room when the lights flicked off and on.

What fuse do I pull? Sorry I am so naive about all this.


I guess Im concerned something will catch fire.

 

[VioletG]

It just happened again. THe lights upstairs did not flicker and I did not turn anything on.

 

[Iggifer]

any changes to your central heating / plumbing recently?

 

[VioletG]

Not recently but it's problematic. It's an Isar combi and always causing problems.

Could a fault on that cause a problem? If so I will switch it off for the night

I'm wondering what is causing the thud. It;s like something comes into play and creates a surge.

 

[Iggifer]

I am by no means a CH expert but it's a common cause of bangs and thuds I believe:-

Stolen from another site

Noisy Boiler
Hissing or banging noises from your boiler or heating pipes are caused by the following:

Scale in the Heating System
The build up of scale can be treated with a chemical descaler, found at most DIY stores. This involves shutting down the system, adding the product and leaving it to work for a few days. The system then needs to be drained, flushed through and refilled.

This can cause 'hot spots' which produce loud bangs from steam bubbles. This can be treated by adding a chemical descaler to the Feed and Expansion Tank, found at most DIY stores. The system then needs to be drained, flushed through and refilled. See Bleeding Radiators for help with this.

Boiler Thermostat is Set Too High or is Faulty
See Faulty Boiler Controls.

Lack of Water or Pressure in the Central Heating System
You will need to double check that the mains water is on. If it is, first turn off your boiler and check your Feed and Expansion Tank - move its metal arm to release the Float valve if it's stuck. Check that the Open Safety-Vent Pipe is correctly installed. Another cause could be that you have Burst of Frozen Pipes.

If the problem is a lack of water pressure, the pressure indicator on your central heating boiler will usually indicate it needs to be increased.

Can also be caused by air in the system, which I believe can be resolved by bleeding the rads when cold

 

[securespark]

It means being without electricity for a while (to the lights at least) but if you turn off the main switch (VERY important!) then remove all the fuses with white dots, then switch back on, that will isolate your lighting circuits.

In case you have a burglar alarm on one of the lighting circuits, do not leave them isolated for more than 8 hours in case the system runs down and the external sounder switches on.

If the banging stops, it's a safe bet there's a fault with something connected to the circuits you have isolated.

 

[VioletG]

Thanks. There was a huge thud and he lights went out in the kicthen and downstairs bedroom where my elderly mother is and has access to bathroom. Those won't come back on.

I can also smell a slight tinge of burning in the living room.

I am scared to turn everything off as it will be complete blackout.

 

[Johnmelad]

Time to get an electrician in I think.

 

[crystal ball]

Sounds similar to a fault I was called to, the thudding noise was caused by a cable fault shorting and clearing itself, never blowing the fuse, found the culprit under a bedroom floor wheer the plumber had nailed through a cooker cable years ago

 

[bernardgreen]

The smell of burning is an obvious danger sign if you cannot identify where the smell is coming from.

Thuds always sound louder at night and may go un-noticed during the day.

Look at anything that has a motor in it.

Motors in fridges and freezers can be very noisy as they come to the end of their life and have difficulty starting. They take excessive current that could dip the lights and make them hopt enough to smell of burning.

Saniflow units ( pumps behind toilets ) are another item that can give similar problems. ( especially if they are chewing up cloth and/or string )

 

[xdave]

You need to get an electrician in quickly, and should isolate the circuits at that fuse box by flipping that switch to 'off' immediately.

Not wishing to alarm you unnecessarily but if you can smell burning and parts of a circuit are permanently shorted then you have a fault that is a serious risk to property and life. If the fuse for that part of the circuit hasn't blown then you have a situation where an appliance or wiring fault could cause a fire so treat it as an emergency. Your smoke alarm going off regularly is a serious concern. Once might be coincidence if there is no obvious sign of smoke, but more than once given the situation in the property and you should be calling for help immediately.

If cost is a concern maybe your building's insurance policy could cover you if there is an immediate risk of fire and potentially existing burning/charring damage?

Although a boiler fault could cause the circuit symptoms, it will not usually set off your smoke alarms. You mention more than one so it is unlikely to be the batteries draining. They are there for a reason so please don't ignore them.

 

[nry]

Got to agree with the posts above here

Upon visiting my grandad a few years ago he had something very similar where you could feel it in the floor vibrating!

Pretty sure it turned out to be the immersion heater, but he also had rats which had chewed through a number of cables shorting them out...

Turn it off now! and get it checked out!