Running combi boiler in "condensing" mode

rob7475

markin said:

2.5c in 1.5 hours seems far to long for this time of year, Are they all bled and trv's open? Set it as low as you can stand, And bump it up in cold weeks.


If you drive at 40mph rather than 70mph it takes longer but should use less 'Gas' up to 15% less.

Yes they're all bled and get hot across the full panel. The house thermostat is in the hallway and the radiator in there outputs around 8000 btu at Delta 70.

I may have to look at rebalancing the system as the upstairs radiators do take a little while longer than downstairs to fully heat up

BUFF

who uses delta 70 these days? We used delta 60 until 2013 when we switched to delta 50 & we are now designing systems using delta 30 ...

(~8000BTU at delta 70=~5150BTU at delta 50)

frostysaver

You mention you've already got a Tado thermostat - how's it wired to the boiler?

Tado reverse-engineered the worcester boiler 'digital' control (known as EMS), and with particular Tado bits that can be used to automatically modulate the boiler. Meaning it runs at the lowest temperature that's sufficient to reach the house temperature needed.

I recently fitted one (second hand thermostat and wireless extender from eBay) and it seems to work well.

See: https:// community.tado.com/en-gb/discussion/7979/worcester-bus-connection

BUFF

afaik  (what Tado support told me) Tado doesn't work with EMS & only runs as a relay on a Worcester Bosch boiler (unless you have bought an Opentherm adaptor from Holland, in which case WB won't warranty your boiler).

They also removed the modulating connectors from the current UK wireless extension module (although you can now buy the European version which still has them direct from Tado's own online pro shop). https://uk.installers-shop.tado.com/products/add-on-wireless-receiver-for-combi-boilers