Old Boiler - One Pipe System - Need To change?

[FriendlyHelp]

Hi

I have a very similar setup to the boiler and information which was provided here some 12 years ago

https://www.diynot.com/diy/threads/conflicting-opinions-a-low-loss-header-or-not.267753/

The boiler is about 30 years old and has steel and copper pipes - There are 18 cast iron large radiators and it is a one pipe system ! Most of it is in steel 2 inch or 1 inch pipework. The boiler is a mexico BED boiler sitting in an outhouse

I had a few engineers come out who said I need to replumb the one pipe but I cant do that for the following reasons:

1. I am a retired pensioner who is 74 years old and don’t want upheavel at this stage in life
2. The house is well decorated and I don’t have the funds to rip it all out
3. The cast iron radiators are very nice and I don’t want to throw them away ad they remind me of my wife who died
4. I prefer to keep things simple and leave everything as vented cylinder and low pressure pipework

I can get a heat only 30KW wall hung boiler from my research either Intergas or Baxi - I can replace the circulating pump as well .

My system has one primary flow and two returns (one from hot water cylinder) and the second return from the radiators from the boiler. It runs in 2 inch pipework

Do I need a loss header or plate exchanger or has technology moved on since 12 years ago? I will stay away from British Gas for install but how do I find a heating engineer who has worked on this sort of system as it is so old and can try and keep it going?

Bonus Question
Will a new boiler make a difference to gas usage (and by what sort of percentage), be more reliable ? AI use about 2,000 pounds worth of gas a year

 

[Exedon]

We regularly work on large one pipe systems normally in large country houses often listed,
We mostly do oil boilers but the principle is the same.
Flush the system get as much crap out as possible.
Separate existing heating system from new boiler with a suitably sized plate to plate.
Obviously new pumps controls ect will be required what depends on existing.
You will probably be better off looking for someone with commercial heating experience who is used to dealing with screwed steel.

 

[flameport]

I had a few engineers come out who said I need to replumb the one pipe

You can't shove a new boiler onto an old system like that, so in some ways that is correct - but only if you want everything removing and replacing with 100% new.

Do I need a loss header or plate exchanger

Yes, unless you want to replace the entire system.

Will a new boiler make a difference to gas usage

It will, but not by as much as the companies beginning with B will claim.

If the existing boiler is beyond repair then you will need a new one.
If not, then repair and keep it.

If the rest is as old as the boiler then look at new controls for what's there, which will be a fraction of the cost of a new boiler but could still save significant amounts.

 

[FriendlyHelp]

We regularly work on large one pipe systems normally in large country houses often listed,
We mostly do oil boilers but the principle is the same.
Flush the system get as much crap out as possible.
Separate existing heating system from new boiler with a suitably sized plate to plate.
Obviously new pumps controls ect will be required what depends on existing.
You will probably be better off looking for someone with commercial heating experience who is used to dealing with screwed steel.

Thank you - That makes sense - I prefer to keep the system if possible - I don’t like the fact I cant control different room temperatures so often leave an electric radiator in the main room and the gas boiler keeps most of the house warm in cold winter

Do you have any north london reccomendations for commercial boiler? The pipework is ok - Its just the boiler that got old

 

[FriendlyHelp]

You can't shove a new boiler onto an old system like that, so in some ways that is correct - but only if you want everything removing and replacing with 100% new.


Yes, unless you want to replace the entire system.


It will, but not by as much as the companies beginning with B will claim.

If the existing boiler is beyond repair then you will need a new one.
If not, then repair and keep it.

If the rest is as old as the boiler then look at new controls for what's there, which will be a fraction of the cost of a new boiler but could still save significant amounts.

Thank you - what controls are you referring to exactly ? I have a timer and room thermostat - Do I need anything else