High gas usage for boiler.

[stevedurban]

So we have a standard 2 splan - one M.valve for heating (which feeds all the radiators in the house) and one one for water.

Tado controls both independently. When the downstairs thermostat calls for heat - it tells the tado controller to open the DHW valve - and boiler starts etc etc. the other thermostats around the house just tell the radiators in their “zone” to open and close as needed. If the downstairs is calling for heat at that moment - the radiators will get hotter. If downstairs isn’t calling for heat - they won’t get hotter. (That’s our choice - and was recommended by tado to do this)

When I was mentioning about hearing the pump - I was referring to the overrun. It sounds like the pump keeps pumping for about 5 mins from the time the last valve closes - and then the boiler is quiet. I presume this is by design.

When either valve is open - you hear the boiler in full force.

You mentioned about the boiler pump running constantly with a call to the boiler to run - and not burning if the output is > the heating demand? But surely if the heating demand isn’t met - the boiler should be burning? And if the heating demand is met (room stat hits temperature) the value would close - and the boiler would stop anyway? So what scenario would the valve be open - but not calling for heat?

P.s - thank you so much for your patience, advice and understanding! I really appreciate it!

 

[ShaunCorbs]

Tbh all looks normal so just higher use

 

[stevedurban]

Tbh all looks normal so just higher use

Can it really be just that??? 185kwh today.

 

[ShaunCorbs]

The meter reads nothing when not on / out

The meter is reporting the correct kWh over time heating / hot water been on around 8 hours total at 24kw

How long has the tado kit been installed?

 

[John.g]

That's correct, all boilers have a minimum output, depending on boiler manufacturer, boiler output etc, it will be ~ say 3 to 6 kw so if the heating demand is below this then the boiler temperature will rise and the burner will cut out when this temperature reaches its setpoint+3C (normally) and the burner will cut back in when the boiler temp is its setpoint-3C plus the boilers anticycling time which may be ~ 3 mins, the pump will continue to run because the demand for heat has not gone away.

"When the downstairs thermostat calls for heat - it tells the tado controller to open the DHW valve" do you mean the CH m.valve? The DHW valve is also controlled by the cyl stat.

 

[stevedurban]

The meter reads nothing when not on / out

The meter is reporting the correct kWh over time

How long has the tado kit been installed?

Correct - the question is is the boiler using more gas than it should?

Tado been installed for 10 years. I added digital tado room stats about a year ago in the hope that it would help… alas it didn’t!

 

[ShaunCorbs]

Doesn’t look like so you’ve had this problem for a while ?

“I added digital tado room stats about a year ago in the hope that it would help… alas it didn’t!”

 

[stevedurban]

That's correct, all boilers have a minimum output, depending on boiler manufacturer, boiler output etc, it will be ~ say 3 to 6 kw so if the heating demand is below this then the boiler temperature will rise and the burner will cut out when this temperature reaches its setpoint+3C (normally) and the burner will cut back in when the boiler temp is its setpoint-3C plus the boilers anticycling time which may be ~ 3 mins, the pump will continue to run because the demand for heat has not gone away.

"When the downstairs thermostat calls for heat - it tells the tado controller to open the DHW valve" do you mean the CH m.valve? The DHW valve is also controlled by the cyl stat.

Apologies yes - when the CH valve will open when downstairs calls for heat!

 

[John.g]

So, what tells the boiler to start when there is a call for DHW in high summer or anytime for that matter when all TRVs are shut?.

 

[stevedurban]

Doesn’t look like so you’ve had this problem for a while ?

“I added digital tado room stats about a year ago in the hope that it would help… alas it didn’t!”

Yes - I’ve had it for over a year - maybe 2. I’ve gone through cycles of trying to find a solution. Each plumber that came - serviced it and said - “it cold - so you use more heat! - and that was it! They didn’t really check anything - never checked the gas meter for usage per min etc… I just couldn’t find anyone with any drive to just confirm their theory! If it is just I’m using more gas - then so be it!

I just can’t understand why for 8years or so of living in the house - my estimated average gas usage on every bill has been 6-10,000 and a bill of around £120 a month (averaged over the year). I’m now heading to an average of 60,000 according to their estimations (185kwh today!)