System upgrade - Combi, Unvented Tank or Gravity fed system - HELP!

ThisIsWeird

Albermarle said:

ThisIsWeird said:

2.5bar, whilst not wonderful, should be perfectly fine for most combi use. The delivered flow should also be measured, tho'.

Many combis are being run on less than 2 bar.

Yes, I would be very happy to just have 2 bar !

Bless.....

k1rkyc

Thank you to each of you for your replies! Lots to think about! We have a plumber coming over this evening to replace the valve on the expansion tank to hopefully stop the overflow pipe from dripping outside…. Well speak to him about all of this also!

sgun

I've recently asked a similar question on the energy boards. My oil boiler is 36 years old and still works BUT it's definitely getting to the end of its life and parts are getting hard to come by. We have a mishmash of different sized pipes and none of the rads are metric sizes. So we are going for a new full heating system.

If I thought the boiler would tick over for another few years I wouldn't be changing it though, I'd wait. 

EssexExile

I'm with friends at the moment who have an oil combi and say it's been fine since they had the tiger loop fitted. I had to Google that.

FreeBear

sgun said:

I've recently asked a similar question on the energy boards. My oil boiler is 36 years old and still works BUT it's definitely getting to the end of its life and parts are getting hard to come by. We have a mishmash of different sized pipes and none of the rads are metric sizes. So we are going for a new full heating system.

If you are fitting a completely new heating system, well worth investigating heat pump options. Even if you don't get one, you should still fit larger radiators & pipes (22mm or even 28mm feed/return plus 15mm to the rads). That will put you in a better position for the day when heat pumps are the only option. Modern oil boilers are condensing, and a very few can also modulate. being able to reduce the flow/return temperature will increase the efficiency.

k1rkyc

So the plumber is going to quote for replacing the rad pipes for new bigger ones alongside a quote for a Combi.
He’s also going to price up to replace like for like. 

At the moment, the upstairs floorboards need to come up to re-route a new hot and cold feed for the downstairs toilet, so he said whilst he’s doing that, if the price is right, we may as well at least consider new rad pipes (and Combi if budget allows) 
This will then mean no more pipes in concrete and a whole new hopefully more efficient system. 

We shall see what the costs are!

ThisIsWeird

Explain to the plumber why you wish to increase the pipe sizes - future-proofing for cooler systems like ASHPs - or else he may wonder.

FreeBear

k1rkyc said: So the plumber is going to quote for replacing the rad pipes for new bigger ones alongside a quote for a Combi.

While you are waiting for him to come back with a price, get a quote for a heat pump. You may well find the difference to be minimal (like +/- £200).

sgun

FreeBear said:

sgun said:

I've recently asked a similar question on the energy boards. My oil boiler is 36 years old and still works BUT it's definitely getting to the end of its life and parts are getting hard to come by. We have a mishmash of different sized pipes and none of the rads are metric sizes. So we are going for a new full heating system.

If you are fitting a completely new heating system, well worth investigating heat pump options. Even if you don't get one, you should still fit larger radiators & pipes (22mm or even 28mm feed/return plus 15mm to the rads). That will put you in a better position for the day when heat pumps are the only option. Modern oil boilers are condensing, and a very few can also modulate. being able to reduce the flow/return temperature will increase the efficiency.

We would love to move to a heat pump but unfortunately no cavity wall insulation so we would need to completely internally insulate before we get one. We get far too much horizontal rain at 40mph where we are! Still got one more quote to come in but my preferred plumber is very open to suggestions so I'll definitely discuss the extra sized rads and pipes when I chat with him to clarify a few things.

FreeBear

sgun said:

FreeBear said:

sgun said:

I've recently asked a similar question on the energy boards. My oil boiler is 36 years old and still works BUT it's definitely getting to the end of its life and parts are getting hard to come by. We have a mishmash of different sized pipes and none of the rads are metric sizes. So we are going for a new full heating system.

If you are fitting a completely new heating system, well worth investigating heat pump options. Even if you don't get one, you should still fit larger radiators & pipes (22mm or even 28mm feed/return plus 15mm to the rads). That will put you in a better position for the day when heat pumps are the only option. Modern oil boilers are condensing, and a very few can also modulate. being able to reduce the flow/return temperature will increase the efficiency.

We would love to move to a heat pump but unfortunately no cavity wall insulation so we would need to completely internally insulate before we get one.

Whilst insulating is always worthwhile (regardless of heating source), it is not mandatory. The rules for the Boiler Upgrade Scheme were recently relaxed, so if your EPC recommended insulation, it is no longer a requirement in order to qualify for the £7500 grant.