Horstmann stat problems

[gselectrical]

Evening all.

I was wondering whether anybody has experienced any problems with Horstman HRT3 room thermostats?

I have had various call outs to a school where a load of these have been fitted to control 1kw panel heaters. The maximum switching capacity is stated as 10A.

Basically I was called there as one of the stats had started crackling. They isolated the Fused spur. When I arrived I removed the stat and found that the insides where burnt out. Originaly I thaught a loose connection must have caused this.

Anyway since then, another 3 have gone. exactly the same problem.

I had another call today where I had used these to control 300W heat lamps. Was told that one of the stats had started crackling, so they have disconnected the lamp. I am going there tomorrow to replace all the stats.

Has anybody else experienced any problems with these or other stats?

Picture below is what I discovered.

Cheers

GS

 

[Andy™]

ive fitted them a few times but only for switch heating on, so not much current.

obviously, something is going wrong with them under load

 

[sparkytim]

Not suitable for that purpose it would seem, As Andy says they are normally only used for Heating system control with 3 Amp protection.

 

[Evans Electric]

Looks like the stated 10A is a little optermistic .

 

[gselectrical]

Not suitable for that purpose it would seem, As Andy says they are normally only used for Heating system control with 3 Amp protection.

They where fitted by another contractor at the school (1Kw load)

I fitted the ones controling the 300w load.

It does state that the maximum switching capacity is 10A. (2.4Kw @240v)

Looks like thats a load of bo11ocks then if they are not even capable of switching 300w.

Cheers

GS

---------- AUTO MERGE Post added at 19:30 ---------- Previous post was at 19:28 ----------

Looks like the stated 10A is a little optermistic .

2.1Kw too optermistic mate!

 

[steptoe]

do they need a neutral?

IIRC those stats require a Neutral to balance the load switching......

I have no idea why, but I have had stats fail in the past for no N , thats what the destructions say anyway.....

 

[Andy™]

where have you been hiding Steptoe?!

 

[gselectrical]

do they need a neutral?IIRC those stats require a Neutral to balance the load switching......

I have no idea why, but I have had stats fail in the past for no N , thats what the destructions say anyway.....

Yes mate they need a neutral. Which they had! Cheers. Gs