Eco-tec add-on to existing boiler - worthwhile?

marshall009

We have been offered an Eco-tec add-on to our existing 15 year old boiler. Apparently this reduces the workload on the boiler and saves 25% or more on the gas bill (at an installation cost of £1400).

It seems to be a reputable offer but I'm struggling to find any reviews (all seem to relate to Vailant boilers pre-fitted with this wheras my boiler is not Vailant and it is a retro-fit)

Has anyone had experience of the Eco-tec system as a retro-fit?

matelodave

£1400 is a lot of money and you could probably get a brand new boiler installed for not a lot more than that. You'd also have a warranty.

The last thing I'd do is spend that sort of money on a 15year old boiler and then find that the boiler died after a year or so.

I'd also be very sceptical about saving 25%. I dunno what your gas bill is but even if it was £800 a year, 25% = £200 which would take at least seven years to pay back and you'd be lucky if your old boiler was going to last another seven years.

I'd be more inclined to put £50 a month away in a piggy bank ready for the day when the boiler does eventually die.

marshall009

hmmmm... thanks for your response. Well, our bill is actually £900pa on gas and although we were quoted 25% savings this is allegedly a minimum and it is typically around £30% (which is why I'm asking around to see if anyone has experience of these systems)

I do believe the Eco-tec is a reputable system as Worcester Bosch boilers now come with it pre-installed.

I understand that a (decent, not cheapo) new boiler would be around £2500 installed so if I can make this one last a few more years I would prefer to do so. When I do get around to a new boiler, this system can be incorporated into it, so it continues to reduce the gas bill even then

System

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/545245/PFGHR_Report_-_FINAL__1_.pdf

Be wary of men citing statistical savings. It is not 30% off your gas bill as standing charges are fixed. Moreover, the biggest savings in gas usage are in households that use a lot of DHW when the gas flue heat recovery system has a thermal store.

marshall009

Thank you Hengus, the system I have been offered is not a heat-recovery system but a method of preventing the boiler from firing up on every cycle when the temp of the water in the system is still high enough to be used in another cycle without being heated again.

I have been googling for 'Eco-tec' but not getting useful results as a retro-fit

Mike

EachPenny

I remember something that sounds a bit like this from many years ago. It was a timer which inhibited further firing of the boiler for a set period of time, rather than just relying on the circulating water thermostat determining the need for firing. The system would still alow the system temperature to reach the maximum, but would allow it to drop a lot further than the point where the system thermostat would normally start firing again.

Not surprisingly, if the boiler fires for less time it uses less energy - but that came at the expense of possibly running the heating system for longer overall in order to achieve the required heat levels.

No doubt something similar is on the market today - and probably far more sophisticated.

What kind of boiler do you have marshall009? If it is a combi then I'd be interested to hear how this device works, as the hot water demand is likely to result in far more frequent firing than the system of old would want to allow - I'm not sure the operating principles would be compatible.

System

Smart heating controls are advertised as being able to achieve savings of up to 40%; however, this figure is based on a house that has no heating controls (e.g. Timer, or thermostat). Most modern controls use what is known as TPI to aggregate the total heating demand to better inform how long the boiler needs to be on. Basic thermostats are nothing more than an on/off switch which results in un-necessary boiler cycling. I have a Honeywell Evohome control system which has reduced my annual gas usage by 20%.

Eco- Tec is just a term that Valliant uses for some of its boilers. Reco - Flue is their flue recovery system. Their TPI control system is called vSmart.

http://www.honeywelluk.com/documents/All/pdf/TPI%20Functionality%20explained.pdf

marshall009

This is the Eco-Tec I have been offered midlandsrenewables.co.uk/ecotec (I am not allowed to post a link

StopIt

marshall009 wrote: »

This is the Eco-Tec I have been offered midlandsrenewables.co.uk/ecotec (I am not allowed to post a link

I would take that 25% saving figure and throw it straight in the bin.


Our boiler has a feature like this, and yes, there are times when it does do exactly as intended. However, a decent wireless thermostat controller can produce similar results for much cheaper. For that cost, I'll be putting the amount towards a new boiler entirely, getting a more efficient system to start with AND this functionality too.

System

Have a read of this article and then ask the person offering you ecoTec to show you its Erp rating and the calculations that underpin the projected savings. FWiW, if you did buy this piece of kit and then connected it to a new condensing boiler then you would probably invalidate the boiler warranty. I have a modern condensing boiler with a 5:1 gas valve modulation ratio (that is, the boiler varies its output from the full 24.8kWs down to 5kWs depending on heat demand) that talks to my control system via a manufacturer approved OpenTherm connection. Together, the controller and the boiler determine the boiler firing rate and gas valve position to achieve maximum efficiency. The bit that worried me a lot in the link was the reference to 'steam'. Modern boilers are designed to 'steam' (that is; eject water condensation) as removing the heat from the flue gases is a key part of the energy efficiency process as is getting the return flow to a temperature which allows condensation (below approx 55C) to occur.

http://www.sunvic.co.uk/blog/posts/2013/august/what-is-the-erp-directive/

matelodave

Reading the Eco-Tec info I'm guessing that for £1400 you get something like this https://www.amazon.com/Differential-Temperature-Controller-Thermostat-Fahrenheit/dp/B01ETRIZUG which strikes me a a rather large mark up.

I reckon it just over-rides the internal boiler stat and only allows the boiler to run when there's a preset temperature difference between the incoming and out going water. Although it probably needs the pump to run to work properly.

You'd be a lot better off splashing out a few bob on a wireless programmable thermostat so you can adjust the the temperatures and times that the heating comes on to suit your lifestyle a bit better, cost around £100 installed.

Reduce the temperature of yor hot water and if you've got a tank, make sure it's properly insulated - add another jacket to it and optimise when you heat it - ideally for an hour or so before you get up for morning ablutions and if necessary an hour before bedtime if there's not enough hot water left. There's no advantage it keeping the tank hot all night or all day if you aren't using it.

Do other stuff like reducing the amount of hot water you use/waste and make sure you've got sufficient insulation in your loft. A bit of draught proofing might help as well.

TRV's on your rads are also worth considering and nowadays you can get programmable sensor heads which will turn the valve on & off at preset times/temperatures to give you a bit more control - they'll even fit your existing TRV's https://www.victorianplumbing.co.uk/terrier-i-temp-programmable-thermostatic-radiator-valve?campaign=googlebase&PS2PVV1=1739&gclid=Cj0KEQjwg47KBRDk7LSu4LTD8eEBEiQAO4O6r5VL9iJTTYR80v_Ljn8gc4U765rA4yGTWXmHFPZ9iwUaAoc-8P8HAQ

All of that will probably cost you less than a couple of hundred quid and could easily save you 20%