Newlec NLSH24AN Night Storage Heater

[Durkee Atwood]

I am new to this forum. I am not an electrician but a competent electronics engineer and I understand electricity, the dangers and my limitations. I always seek professional help for certifying any electrical work. I thought this was a necessary statement just in case it hampered a fully qualified electrician in offering an amateur electrician advice or opinion.

I have a Newlec NLSH24AN night storage heater. It has been working well for over five years. Recently it has stopped working. I have done the obvious: checked RCD in distribution board, checked that the neon light at the main switch is on (at night). There is power to the switch. I have isolated it and checked continuity of the switch actuator. I have checked continuity of live and neutral from the switch to the terminal block inside the heater (plastic terminal block) and that checks out OK. On checking continuity from the ceramic terminal block to the thermostatic control back to the plastic terminal block...nothing. On checking continuity on the input control the limit thermostat shows no continuity. The input thermostat shows continuity. Across the two there is no continuity. Can I assume that the limit thermostat has failed? Is the limit thermostat controlled by the room sensor thermostat and could that have failed? Or am I missing a trick here? Cost of replacement limit thermostat

 

[Doc Hudson]

Welcome to the forum Durkee Atwood, I think these devices normally have some sort of internal thermal cut-out, but I shall leave that for the other guys to answer better than I could. Also I have moved this thread to the more appropriate "Central Heating & Storage heaters, etc" forum.

Doc H.

 

[NozSpark]

Normally the over temp is either a thermal link (melts when it gets too hot), a thermal fuse (looks like a small foil capacitor) or a resettable stat.

There are normally 3 reasons for the thermal link going..

1. It's old and just gives out

2. Clothing put on heater to dry out

3. Input stat broken and allowing the heater to just heat up and up

Otherwise it could be the elements that could be faulty,, they are normally 850w so that will give you a resistance of round about 62ohms per element.. note that they are wired in parallel so if you measure them all connected it's your 1/R = 1/R1 + 1/R2 + 1/R3 equation

 

[sparkytim]

See Thread "TSR 24 AW FAULT ALERT"

It may be same problem as the Manufacturer seems to be the same for all Storage heaters

 

[Durkee Atwood]

Normally the over temp is either a thermal link (melts when it gets too hot), a thermal fuse (looks like a small foil capacitor) or a resettable stat.There are normally 3 reasons for the thermal link going..

1. It's old and just gives out

2. Clothing put on heater to dry out

3. Input stat broken and allowing the heater to just heat up and up

Otherwise it could be the elements that could be faulty,, they are normally 850w so that will give you a resistance of round about 62ohms per element.. note that they are wired in parallel so if you measure them all connected it's your 1/R = 1/R1 + 1/R2 + 1/R3 equation

The thermal link that you mention that is in the diagram I have of this model does not exist on this heater. Also, the input control that is connected to the room thermostat is different to that shown on the diagram downloaded off the net, which is a little worrying.

Thanks for the input. You have reminded me of the first rule of testing in that I should continue to test the elements rather than stop and assume its one isolated fault. I will test these in order to eliminate them from my enquiries as all good detectives would say. On crimewatch UK...some want members of the public to come forward so that they can eliminate them? That always seems a bit drastic to me but I guess the logic there is that the last man standing is the culprit.

The input stat shows a 2 ohm-3 ohm resistance but I can't find any data for that.

 

[Durkee Atwood]

I have just read my initial thread and the opening statement reads more than a tad "know it all." It sounded better in my head at the time. What I should have stated was that I am moderately skilled in electrical work. Keen to understand electrical installation but require the help of a professsional or experienced person now and then and ready to accept safety advice whenever it is kindly given. Otherwise I am extremely humbled by your unstinting capacity to spend your time giving advice to an enthusiastic amateur such as me. I now need to wash that mark off my nose. Yes I know its a serious subject and I promise that when I make a joke or two I do it with the mains off.

I do appreciate the replies I have had so far and in such a short time.

Thanks folks

 

[NozSpark]

I just thought that I'd have a look for the model number of your heater to see if it'll help..

if you look here it shows some input stats.. I think the over temp is combined into this unit IIRC (towards the left on the picture).

Now coming towards the front from the screw hole at the rear is where the over temp bit is and this can be reset with a small screwdriver (((POWER OFF))), you just push down lightly where it looks like a gap.. you will hear a click when it's reset!

If you still think that this is still the problem then it's <

 

[Durkee Atwood]

I just thought that I'd have a look for the model number of your heater to see if it'll help..if you look here it shows some input stats.. I think the over temp is combined into this unit IIRC (towards the left on the picture).

Now coming towards the front from the screw hole at the rear is where the over temp bit is and this can be reset with a small screwdriver (((POWER OFF))), you just push down lightly where it looks like a gap.. you will hear a click when it's reset!

If you still think that this is still the problem then it's <

 

[NozSpark]

When you tested the elements did you have them removed from the NSH or were they still in circuit??

If you have one that is 11ohms out of circuit then it is faulty and needs replacing.. luckily you have about 6 months to do it now before you need them again!!

If you want to test the NSH and still have a faulty element then it will run OK with an element missing, the heat will just be a bit uneven within the unit.

 

[Doc Hudson]

Not sure if this is any help, http://www.torreelectrics.co.uk/acatalog/Newlec_Storage_heater_spares_NLSH_Automatic.html But it appears to be a diagram and spares list for a Newlec NLSH heater. I cannot vouch for the particular company, but it does look like a decent parts list?

Doc H.

 

[sparkytim]

Sounds like you have fixed it

11 ohms is not that far out for a 3.4 Kwatt 4 element heater (with all elements connected)

It probably just over heated and the cut-out opened.

This often can happen when the Main input stat sticks and is nothing to worry about.

See how it goes and if you get repeated episodes of the same thing then you probably need a new Input thermostat.

 

[Durkee Atwood]

It works...that flimsey reset was tripping out. My detective work didn't show conclusively that an element had gone. When I removed said element completely and checked its resistance it was fine. The culprit, after interrogation, was the wife. It went something like this:

Q: You haven't put any damp clothes on it have you?

A: No

Q: Have you put anything in font of it to dry?

A: No...you told me not too.

Q: So nothing's been put on or around the heater at any time?

A: No...apart from a few envelopes that came through the door.

We had been away for a few days and the junk mail had piled up. She placed the pile of envelopes on top and near the controls. Of course it was cold when they were placed there. By mid morning the offending items had been removed and the fact that the heater was not as warm as it should have been not mentioned until the next morning when it failed to work.

The good thing is that it cut-out as it should do when it overheated. My wife now knows first hand why there is a notice on top about placing things on the heater. We are both better informed and it hasn't cost me a penny.

Thanks everybody for your comments and advice it really did keep me cool and focused on why it stopped working. It also gave me the opportunity to use the 500W lamp I bought for interrogation purposes (the wife has a lovely tan now). No...that was a joke...I would never ever point a lamp at anyone! I might wire them up to a capacitance discharge of a few thousand volts...low current though.

You have not only saved me money but you have helped prevent a marriage breakup of 25 years....she actually thought I would be concerned about the post getting scorched so didn't mention it.

 

[sparkytim]

Don't be to hard on the wife these things happen, glad you got to the bottom of it and solved the problem.

 

[NozSpark]

The main thing is that it's sorted now..

and you ow know what happens when you put things on your storage heaters!!

Locked to prevent being resurrected (again)