Rated 5 out of 5Â by Attwoods Compatable replacement.
I'm an electrical contractor. I was called to a house that had a Horstmann Diamond programmer built in the 60's which was now sometimes sticking.
I Spoke to Horstmann technical who suggested Horstmann 425 Tiara Programmer. What an excellent choice, a breeze to install and all working o.k.. If this one lasts as long as the old Horstmann Diamond, the customer will be well happy. This item was cheaper from Screwfix than any of my electrical wholesalers.
Well done Screwfix.
23 Jul 2014
Rated 2 out of 5Â by MikeASC Horstmann Tiara 425
I was initially quite impressed by this programmer: it seemed to work satisfactorily, and appeared to be good value for money. However, after approx 18 months of operation, I experienced erratic operation of my heating system: domestic hot water (DHW) worked OK, but central heating often failed to start. (My heating system uses a motorised 3 port valve, and both DHW and CH are pumped.) After much investigation, I found that the fault was caused by intermittent closure of the DHW switch, when in the "off" position. I have dismantled the mechanism, and the fault is caused by poorly toleranced plastic in the switch leverage system.
I would NOT recommend this product.
5 Nov 2013
Rated 5 out of 5Â by tinwhistle Simples
Good basic Programmer
Doddle to fit
Does what it says on the tin
5 Oct 2013
Rated 5 out of 5Â by Acker Best make of heating control
This heating control box was easy to fit and easy to set for programming etc. The price was competitive and prompt delivery.
25 Dec 2012