Back boiler and oil heating

I had a plumber today no heating in my house, no rads just copper cylinder. He is putting in 8 rads double, oil tank, 26kw Enviromax condensing boiler, Grant backboiler. I asked him could he put in the zones up stairs and down stairs said he couldnt with a back boiler??? Also i asked him to put in a switch just to heat water during summer months from oil said i would have to turn off all rads to do that. I said i didnt i didnt want to be messing with rads etc. Having to airlock them etc. He said there could be an explosion if switch was left on by a mistake or electricity was cut off. I spoke to a man in work he has a boiler stove heading rads and oil heating. Has switch to heat water only from oil and also zoned up and downstairs its sauter control panel system. I am getting thermo stats on each radaitor. Can some one please shed a light. Thanking you.

It can be done as you want but its beyond the skill level of your plumber.

If you look on this site http://www.systemlink.ie/ you will find different piping configurations

The issues are as follows:
Suppose the fire is going full blast and there is a power cut, the circulation pump on the back boiler will stop and the boiler needs to be able to dissipate the heat pronto.

The way it is done is that there is an inch pipe from the back boiler straight up and venting into your header tank.
There is a direct 3/4" cold feed from the header tank into the return pipe into the bottom of the boiler.
There are NO, I repeat NO, obstructions such as pumps, non return valves, stop cocks, nothing on these pipes.
The idea is that the water will circulate by gravity alone between the header tank and the boiler while it cools down

\Some folk put in a rad in a room above with two lock shield valves to act as a heat sink.

Having said all that and done many of them for folk, I dont think its the best idea in the world

It's definitely possible and such systems are standard.

I did this in my last house, you need a hot water tank with 2 heating coils, one for the oil boiler and the other for the back boiler, pipe in as previously explained by ircoha. Fitting a zone valve is no problem as long as it does not cause restriction to the header tank

Of course it can be done, I have exactly this setup.
Oil boiler, stove with boiler. Separate control of 2 zones. When using oil or stove.
Control of heating only water on oil.
Solid fuel boiler will always heat water.

The stove/ back boiler must be piped to your cylinder with no obstruction to gravity flow with inch copper piping. Best if the run is not too long.

The only impediments to doing it this way is that the primary/gravity run to cylinder is too long, Cylinder is not high enough, Or your plumber is a lazy idiot.

Don't accept any bull about not being able to zone both heat sources.