Reducing fuel usage in a thirsty boiler

[Ian L]

Hi,

We bought an old house in Aisne in August which has a relatively new De Dietrich 'fioul' boiler in the cellar. It heats around 9 radiators and the hot water system. We are unfamilar with such a heating system and have listened so far to the advice of the previous owners. We stay at the house just two weekends a month and we were told to set the heating to '3' (its minimum setting) when we leave the house in summer and '4' during the winter so the pipes dont freeze. We have followed this advice but we've realised that, particularly recently, that the boiler is using a lot of fuel whilst we are away (around 100 litres a fortnight). All the radiators are on the frost symbol (except a single master radiator that cant be altered) and the boiler is set to 'manual' and therefore not using the room thermostat.

I read in the faq entry about anti-freeze for the boiler radiator system. Is this a possibility and if this is present is it OK to turn off the boiler between visits?

Any advice would be really appreciated as its costing us a lot more than we expected.

Ian 

[Owens88]

We have anti freeze ('anti-gel' ) in our radiators. We also leave the thermostat to frost (but its indoors so I suspect it woiuld kick in quite infrequently).

 

However no proof that any of it is working !

 

John

[PaulT]

Sounds fairly frugal in its drinking habits if it is on 24/7...

The PO of our house used to leave the boiler on a time switch so that it came on 2 hours in the morning and 2 hours in the evening. They also marked the fuel level on each of their visits.

I on the other hand have installed a thermostat and set it to about 8 degrees. Fuel usage is far lower. Just need to fininsh the little control device I am building, using a couple of timers, so that I can set the boiler a couple of months in advance to come on full time a couple of days before our winter visits so that it is nice and warm.

Paul

[Anton Redman]

I think the boiler control control which you have set to three controls the maximum amount of heat the boiler will produce. It is running at that setting all the time and the heat is being 'dumped' to the single radiator with no thermostat. I suggest you try running for a fortnight with the room thermostat on say 7 degrees which should mean once the room is at that temperature the boiler shuts back to pilot light

[Poolguy]

[quote user="Ian L"]

Hi,

We bought an old house in Aisne in August which has a relatively new

De Dietrich 'fioul' boiler in the cellar. It heats around 9 radiators

and the hot water system. We are unfamilar with such a heating system

and have listened so far to the advice of the previous owners. We stay

at the house just two weekends a month and we were told to set the

heating to '3' (its minimum setting) when we leave the house in summer

and '4' during the winter so the pipes dont freeze. We have followed

this advice but we've realised that, particularly recently, that the

boiler is using a lot of fuel whilst we are away (around 100 litres a

fortnight). All the radiators are on the frost symbol (except a single

master radiator that cant be altered) and the boiler is set to 'manual'

and therefore not using the room thermostat.

I read in the faq entry about anti-freeze for the

boiler radiator system. Is this a possibility and if this is

present is it OK to turn off the boiler between visits?

Any advice would be really appreciated as its costing us a lot more than we expected.

Ian 

[/quote]

It may be a bit 'off topic' but I have a radical suggestion to make.

You could fit an evacuated tube solar array with its hot water storage.

This would achieve two advnatages. First is that you would get all the

hot water you want for free. Second, it would preheat the water feed to

the boiler all year round, so that your minimum settings could be

provided by the solar system and therefore the thermostate from the oil

boiler would rarely fire up the juice. That should save you an

enourmous amout in oil  cost... especially now that oil has

broached the $100 per barrel mark you can just sit back an watch those

prices rise with only minimal impact on you yearly fuel bill.

I should emphasise that Solar alone is not a solution for space heating

unless you have underfloor system which works on relatively low

temperatures. But Solar is excellent as a Preheater - I am just putting

this system on my house.. at the moment its running on bulk storage gas

and its costing a fortune to heat the joint. My payback is 2.5 years.

Andrew

[Alex H]

quote user = Poolguy

Second, it would preheat the water feed to the boiler all year round, so that your minimum settings could be provided by the solar system and therefore the thermostate from the oil boiler would rarely fire up the juice.

 

Correct me if I'm wrong, but are the hot water and heating water not entirely seperate circuits?

Have you got a 'special' configuration for your system, because I'm pretty sure mine does not work as you've described

 

[Poolguy]

Ah yes, it purpose built, so that either the HW cylinder is inside the bulk storage or that they are seperate with a changeover switch so that HW gets the first look at avaialbe heat and then all extra goes into the bulk storage to be redistributed to the oil boiler. Its quite simple really, and can be as powerfull as you want. I am putting 4  x 30 tube 58mm panels on roofside which will generate about 110kw in full sun. Its sized naturally for the Winter rather than the summer so the output will be less than that.

Andrew