Oil Combi boilers

Asdfgh2020

Have a 20 plus year old oil boiler that is on its last legs according to guy who gave it it’s last service and especially the burner.....the circulating pump also needs replacing. It’s your typical ‘open system’ set up as in boiler heats rads and coil in the copper cylinder for hot water.....We’ve looked into air to water heat pump etc and pv cells on roof but the payback is too long for the capital investment which would be close to €12,000......so hence thinking of keeping things simple and just changing out the boiler and circulating pump despite how ‘un-green’ it is......(gas main is quite close to us as in less than 100m but Bord Gas looking for a contribution of €8,000 to provide a connection).....so looking at options at the moment and am wondering if a ‘combi’ type boiler would be worth considering.....does anyone out there have experience of one...?.....I’ve heard they can struggle when the demand for hot water is high and the number of take offs exceeds 3/4........?

zg3409

Asdfgh2020 wrote: »

Have a 20 plus year old oil boiler that is on its last legs according to guy who gave it it’s last service and especially the burner.....the circulating pump also needs replacing. It’s your typical ‘open system’ set up as in boiler heats rads and coil in the copper cylinder for hot water.....We’ve looked into air to water heat pump etc and pv cells on roof but the payback is too long for the capital investment which would be close to €12,000......so hence thinking of keeping things simple and just changing out the boiler and circulating pump despite how ‘un-green’ it is......(gas main is quite close to us as in less than 100m but Bord Gas looking for a contribution of €8,000 to provide a connection).....so looking at options at the moment and am wondering if a ‘combi’ type boiler would be worth considering.....does anyone out there have experience of one...?.....I’ve heard they can struggle when the demand for hot water is high and the number of take offs exceeds 3/4........?

I think combi are very unpopular here (as in no hot tank) as the mains water pressure supply is typically low, and a combi heats cold mains water to boiling but the pressure is limited to mains pressure, or less if heating cannot heat at that rate.

In terms of new oil boiler, wood pellets is an option, but you need more storage space vs oil and pay back is low due to low oil prices.

Newer oil burners are condensing, in that they emit white steam up chimney, and drip water into a drain. They are slightly more efficient but bigger and you might need different chimney.

If its just a new burner you need, keep old boiler, then that's very straight forward. Heating timers and thermostat will save a bit on use, attic insulation is first go to to save heating costs.

Maybe post a photo of burner, chimney and timer/controls. There is nothing wrong with an open system, many 40 year old systems going strong.

Asdfgh2020

zg3409 wrote: »

I think combi are very unpopular here (as in no hot tank) as the mains water pressure supply is typically low, and a combi heats cold mains water to boiling but the pressure is limited to mains pressure, or less if heating cannot heat at that rate.

In terms of new oil boiler, wood pellets is an option, but you need more storage space vs oil and pay back is low due to low oil prices.

Newer oil burners are condensing, in that they emit white steam up chimney, and drip water into a drain. They are slightly more efficient but bigger and you might need different chimney.

If its just a new burner you need, keep old boiler, then that's very straight forward. Heating timers and thermostat will save a bit on use, attic insulation is first go to to save heating costs.

Maybe post a photo of burner, chimney and timer/controls. There is nothing wrong with an open system, many 40 year old systems going strong.

Thanks for response......firstly reliable plumber whom I would trust advised that Boiler and burner are eff’d.....old firebird type controller/timer is the circular dial with the ‘pop up/down teeth’ around the circumference.....one popped down turns on boiler/burner for 15 mins, two down gives 30 mins etc..... system is zoned.....as in hot water (cylinder heated by indirect coil and/or immersion) up stairs and downstairs radiators can be turned on or off but only manually by ball valve in hot press......attic is insulated but could do with more I suppose only have depth of ceiling joist which is 175mm.....also the exiting boiler/burner is located in the utility room which we would like to relocate to maybe outside....I believe most new boiler/burners can now be externally located.? There are currently 16 radiators in house some double some single.

Any suggestions regarding a new boiler/burner welcome.....the combi boiler sounded good based on the vids on them I saw on the net....but as pointed out above maybe not the best solution....?