Immersion heater problems...

[NozSpark]

I replaced 2 x immersion heater elements for a client (E7 and BOOST) a month or two ago.

Recently she has been complaining of that it's making a noise at about 4am like a kettle boiling and some banging... now the elements that I put in have safety stats so they should never allow the immersion to boil up, but I have been back and firstly lowered the temperature (when installed they were factory set and not adjusted) and I have since been back and replaced the stat!

They are supplied from a "horstman" timer

Today I got another call saying it's still making a noise:_|

anyone got any ideas before I go back for a third time.

 

[Sidewinder]

Some sleeping tablets for the customer so they are not up at 04:00?!!!

Seriously, nothing springs to mind!

However, YES, check the tank venting?

Plumbery yes, but...

Nothing else at this second, will try to give it some more thought!

Paul

 

[NozSpark]

Cheers Paul,,

This is positively doing my head in at the moment... there is no way that the immersion elements should be causing this noise..

I was wondering if the expansion pipe was blocked/restricted and pressurising the cylinder a bit????

BTW there is no other water heating in this property!

I think I'll have to go back, advance the Horstman and hang around for a bit to see if I can duplicate what's happening

Anyway,,, what happened to you the other week Paul???? I thought that you were going to give me a ring and pop round for a brew!

 

[Sidewinder]

Sorry buddy, things are all going a bit PeteTong on a regular basis at the moment.

I am hoping to sort thigns out and have 2-4 weeks up your neck of the woods in the next few months.

I ain't been back since we spoke.

LOADS of bad things going on, those wh know me, you included know what I mean.

Things are not good here at the mo, but I am hoping to sort things by Sept.

Please Lord!!!!!!!!

 

[Robin Spark]

I think she really wants Noz round there at 4am making some noise and doing some banging! She's dreaming about you mate

Apart from that, sorry Noz i have no other useful suggestions.

 

[Theorysparky]

air in the system ??

did you drain the tank ??

 

[NozSpark]

air in the system ??did you drain the tank ??

I did drain the tank..

it has a top entry element and a lower side entry one... I think that the lower one was added later as it does not look like a formed boss, more like a soldered in flange.

I think I'll go back tomorrow, make sure that the right element is coming on at the right time (maybe change the top element stat) and see what happens over half an hour or so..

the only other thing of note is that the ball valve is dripping a little bit, but not enough to overflow the header tank

 

[Theorysparky]

had this prob a while back after a plumber had fitted a new mixerr shower

he had refilled it and there was an air lock which caused all the pipes to vibrate loudly.

have you tried the vent nipple ????

 

[NozSpark]

Could be an airlock..

If there is a mixer tap I'll seal up the outlet and turn on both taps and hopefully flush it out through the overflow

 

[Theorysparky]

let us know what the fix was !!!

 

[jl-heating]

test the temperature of the outcoming water... 60 degrees max ...

remove the top fitting sometimes if the water has been boiling it stratifies and salt build up in the top fitting.

set the timers for only the top coil to come use the bottom as a boost so dont put it on a timer and use as needed.

you mentioned you have swopped the stat maybe changing the whole unit would help.

removing the unit would help to tell you the condition inside the tank.

fit a lime fighter on the cold main in the feed tank or mains water in.

if the immersions are 27 inch i would fit a 11 inch on the boost and a 27 inch on the top one ..

it can only be kettling so really you need to know the water temerature when its banging .

 

[Theorysparky]

Kettling ????

whats that ???

 

[jl-heating]

when u boilel a kettle at boiling pint it bubbles and airbubbles make a rumbling noise.

we call it kettling. example if a boiler has a blocked heat exchange it heats up in the exchange faster than it leaves it so it makes a bubbling nose... ie kettling

same here for the cylinder if its to hot air bubbles are produced and make a noise going up the vent ..

 

[NozSpark]

So what's the best bet for this as I've had enough of it now...

First off it's only a small cylinder (maybe 15" or 18" diameter) no jacket and not heated from any other source.

I was called to this property because there was no hot water.. I found that the bottom element was open circuit and whilst the boost element worked it didn't have a safety stat so while the tank was drained down I replaced it... IIRC I put in 2 x 11" elements..

From what I remember the tank looked to in good condition internally, although I did not "finger the outlet" to check for blockages... wish I had now

So the bottom element is the E7 and the top element is the BOOST at the moment.

When I first went back I lowered the temp on the E7 stat by about 5 degrees and it still it "kettled" so I replaced the stat completley and it "kettled" again. The elements are fed from a "Horstman" timer.... Both stats are now safety stats!

You recon that I should check the water temperature,,, what if it's only 60 -65 deg? does that mean the outlet's blocked?

Up to now I've been going back FOC, but if I'm going to be draining it down again because there's a tank issue I'm going to have to start charging again!

 

[jl-heating]

turn it down most people have it less than 60 anyway .. most people want it at 50 degrees... there is an issue with legenella at this temperature but there has never been an istance in a dometic property so dont worry about it ..

44 degrees is the max temperature of a hot outlet in scotland and is to be bought in soon in england..

 

[NozSpark]

UPDATE...

had a phone call a couple of weeks ago saying it wasn't so bad now so not to bother going back.

BUT TODAY I had another off the "next door electrician" and the lady herself saying it's boiling again.. The neighbour didn't do it as he was on holiday when I went round..

Going back on Friday to have another look will take a stat set to 50 deg C with me and see how it goes.

 

[unshockable]

Also the vent pipe should run up in to the loft and bend over in to the tank, so you can check to see if it is blocked, and agree also start the tempreture way down and then work upwards, instead of way up working down

 

[NozSpark]

I'm at the job right now. Stat set to about 50 c and water comes out of tap at 45 ish. It still sounds like its boiling....

So its a plumbing problem.

 

[jackfrosty]

did you find out what was wrong exactly in the end?

 

[Apache]

did you find out what was wrong exactly in the end?

He didn't. Had no clamp meter you see