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Energy bills have been increasing. There are still ways to reduce this.

Case Study – Boiler, Controls and TRVs – Vaillant Ecotec 624 with Honeywell Controls

Job overview: A 3 bedroom house with open vent heating system and hot water cylinder had it’s boiler replaced. The boiler was a Vaillant system boiler. Honeywell S Plan controls.  The manual radiator valves were upgraded with TRVs.

The system was converted to a  sealed heating system with system boiler. New controls installed as well as new wiring. The system was powerflushed and the radiator valves upgraded.


Components used

Vaillant Ecotec Plus 624 System boiler

ST9400C Programmer

T6360 Room thermostat

L641 Cylinder stat.

Honeywell Zone Valves.

Altecnic Ecocal TRV sets.


Post completion review:

The customer was inclined towards a Vaillant 630 boiler, however using our experience we convinced them not to oversize the boiler, therefore we settled with a 624. Our calculations suggested even a 618 would have been more than enough, however sometimes peoples perceptions sometime overrides more correct solutions due to fear.

The preference is to have domestic hot water priority, however in this property where there will be tenants, the landlord has requested everything to be kept simple as possible.

Switching to Altecnic Ecocal TRV is a solid and reliable valve. It has the ability for it’s seating to be replaced on the live. See our TRV valve replacement article.






Disclaimer: Information on this website is provided for informational purpose therefore we cannot accept liability for subsequent problems. All repair tasks should be carried out by qualified trades people. We may also receive commission payments when you are taken to external websites and complete purchases from third party sellers, once you leave our site, we cannot be held liable for your purchases.