Quick question about an old oil boiler?

[gilford]

I have recently moved to a new (to me) house. It has got an old oil boiler which is used to heat the rads and also the water. It is quite an expensive boiler to run (1000 litres of oil in 3 months over xmas!) so I have had it serviced etc to help matters. The guy told me the boiler is very old, and the 88% efficiency he got it running at was the best I'd get from such an old thing

I have had the heating and the hot water come on at the same time since moving in (2hrs in the morning and 4 hours in the evening).

What I need to know is now that spring/summer is nearly here and the heating wont be needed as much, is it more economical to have the hot water come on on its own or will it cost just the same to have the heating on also?

Another thing that has been puzzling me...........

Some people say it is easier and cheaper to leave the hot water on constant is this true, especially with an old system like mine?

Cheers for the help!

 

[leakydave]

A condensing boiler would use less oil, but would take a very long time to pay fir itself.

One thing you may consider is a wall stat if you don't have one, as a lot of older systems only use the thermostat on the boiler itself to regulate heating. To save a lot of hassle a wireless stat can be fitted with minimal disruption to walls/floors... some on here don't like them but I've never had a problem with one.

The stat is best situated in a hallway 1500mm from floor level, away from direct heat/sunlight. The nearest radiator should not have a TRV fitted. This would only turn on the heating when the temp fell below a certain level...

just a thought...

 

[Terrywookfit]

A condensing boiler would use less oil, but would take a very long time to pay fir itself.

One thing you may consider is a wall stat if you don't have one, as a lot of older systems only use the thermostat on the boiler itself to regulate heating. To save a lot of hassle a wireless stat can be fitted with minimal disruption to walls/floors... some on here don't like them but I've never had a problem with one.

The stat is best situated in a hallway 1500mm from floor level, away from direct heat/sunlight. The nearest radiator should not have a TRV fitted. This would only turn on the heating when the temp fell below a certain level...

just a thought...

If the old boiler is running at %88 efficiency, Then a new boiler will never pay for its installation costs in fuel saving !

 

[gilford]

Cheers for the info

What about the hot water though?

Cheers

 

[MANDATE]

I have a similar set up.
It got to cost less if you just have hot water on. The heating is the costliest part.
We don't leave hot water on all day, cylinder is well insulated and there is never a problem.
1000 litres in winter last about 4 months next 1000 litres last about 8 months.
And I think my boiler qualifies for being old, installed 1973.

 

[gilford]

sorry, so are you leaving the hot water on constant or not?


Cheers

 

[Kes]

Yes, 88% efficiency is amazing, puts it in Sedbuk A, or at least B+. Not that I believe it for a minute: how did the service engineer come to that figure?

Two hours in the morning and four in the evening is not a lot. 1000 litres in three months is not tooo much either, about 11 ltrs a day. We use about 12 ltrs/day, but it depends on many factors, size of house, construction, how many users, how hot/tight you are.

We don't have the hot water on constantly, just when the heating is on. Again it depends how much you use. It is more expensive to have the boiler cycling all day (assuming vented gravity system). In fact we don't use the boiler for hot water when the heating is off, we use the immersion heater which takes about 4 units a day (it is on constantly as it isn't on a time switch). That's 30p. The boiler would have to burn less than 10 minutes a day to produce 4 kwh and that's unlikely. The boiler has to heat itself, warm the utility room, heat the pipework etc, so there's a fair bit wasted.

 

[gilford]

I don't have an emersion fitted so I'm stuck with using the boiler

So come summer it will be easier to have the boiler heat the water for an hour in the morning and in the evening then?

The engineer had some sort of computer which he showed me the 88% on?

Cheers