High gas usage for boiler.

[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!)

 

[ShaunCorbs]

Only thing I can think is the tado is trying to heat the rooms often instead of a central room stat coming on once maybe twice an hour the tado is bring it on every 2-5 mins as the room temp fluctuates / drops

185x365 67k kWh so seems in the realm of correct

 

[stevedurban]

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?.

Tado had a schedule that tells the boiler when to be on. Before I used to have it on 24x7, but after our chats it’s now just 2 hours a day.

When tado tells the hot water to be “on” - the tank stat is then monitored and when the water drops below its Temp - it fires the boiler and Opens the valve.

 

[stevedurban]

Only thing I can think is the tado is trying to heat the rooms often instead of a central room stat coming on once maybe twice an hour the tado is bring it on every 2-5 mins as the room temp fluctuates / drops

185x365 67k kWh so seems in the realm of correct

185kwh x 365 days is 67525kwh. Is that a normal Amount? Maybe I have unrealistic views? Id checked online and it seemed to suggest around 10-15000 was average to high for a 4 bed house.

 

[John.g]

185kwh/17.5 heating hours is 10.6kwh/hr so one would expect to see very high room temperatures?

 

[stevedurban]

185kwh/17.5 heating hours is 10.6kwh/hr so one would expect to see very high room temperatures?

We have the rooms around 20/21 degrees max.

 

[ShaunCorbs]

185kwh x 365 days is 67525kwh. Is that a normal Amount? Maybe I have unrealistic views? Id checked online and it seemed to suggest around 10-15000 was average to high for a 4 bed house.

Depends how long you have the heating on/ your system

That figure will be for a dumb system eg central stat

 

[John.g]

Tado had a schedule that tells the boiler when to be on. Before I used to have it on 24x7, but after our chats it’s now just 2 hours a day.

When tado tells the hot water to be “on” - the tank stat is then monitored and when the water drops below its Temp - it fires the boiler and Opens the valve.

So once again back to square one with that huge usage last summer with no logical reason as there was no demand for CH.

 

[ShaunCorbs]

185kwh/17.5 heating hours is 10.6kwh/hr so one would expect to see very high room temperatures?

If the boiler is running at 24kw tho due to the flow being enough for high fire

 

[ShaunCorbs]

So once again back to square one with that huge usage last summer with no logical reason as there was no demand for CH.

Unless there was and the op didn’t notice ?

 

[stevedurban]

Tado had a schedule that tells the boiler when to be on. Before I used to have it on 24x7, but after our chats it’s now just 2 hours a day.

When tado tells the hot water to be “on” - the tank stat is then monitored and when the water drops below its Temp - it fires the boiler and Opens the valve.

Depends how long you have the heating on/ your system

That figure will be for a dumb system eg central stat

We sort of do have a central stat. There is only one stat that’s downstairs that can call for heat. It’s set to 21 degrees and is on from 6-9pm. The rest of the house is basically just TRV’s (the external thermostat just makes the TRV’s more efficient by sensing the temperature in the room - rather than the temperature on the TRV itself)

 

[stevedurban]

Unless there was and the op didn’t notice ?

Let’s say I didn’t notice (very possible) - and the heating was on. It wouldn’t be higher than 21 degrees as the TRV’s and thermostats would have controller it) and with the hotter weather outside - it shouldn’t have taken much time keep the house at that temperature. So it still wouldn’t really explain?

 

[ShaunCorbs]

And there not conflicting with each other eg trvs shut down but stat still calling ?

 

[ShaunCorbs]

Let’s say I didn’t notice (very possible) - and the heating was on. It wouldn’t be higher than 21 degrees as the TRV’s and thermostats would have controller it) and with the hotter weather outside - it shouldn’t have taken much time keep the house at that temperature. So it still wouldn’t really explain?

Depends what time you have it set for off ?

 

[ShaunCorbs]

It might be worth converting the system back to a dumb one for a month and see the usage as Jan and feb are normally similar

 

[John.g]

I would expect a "normal" house to need ~ 5/6 kwr/hr to keep it at 21C so 17.5hras @ 6 = 105kwh/day, i heat mine over the last few days 16 hr days for ~ 75/90kwh BUT my (4) bedrooms are kept at 16/18C, all downstairs kept at 21/22C.

 

[ShaunCorbs]

Plus hot water at around 30kwh ish as depending on usage

 

[stevedurban]

Depends what time you have it set for off ?

And there not conflicting with each other eg trvs shut down but stat still calling ?

Heating always goes off at 9

It’s possible - although I’ve tested time and time again with the downstairs stat. Pushing to 25 degrees and the ch valve opens - putting it to 5 degrees - it closes. I’ve never seen it not do it! But it’s possible it malfunctioned - but I guess the questions is:

The house was 17.9 degrees at 6am this morning before the heating came on. It was set to 21 degrees and we were in all day. It used 185kwh to try and keep it at 21 degrees. If that’s to get expected - then your view of “I just use more gas” could be right?

 

[John.g]

Dumb can be the smartest in the end as long as you don't need room temp control to the nearest 0.1 or 0.2C.

 

[John.g]

How many rooms are you maintaining at 21C, the whole house?.

 

[ShaunCorbs]

Dumb can be the smartest in the end as long as you don't need room temp control to the nearest 0.1 or 0.2C.

That I think is the problem each room has its own stat that’s opening and shutting prob 1-2 degrees and firing the boiler up for maybe 5 mins each time