Advice on new boiler for one pipe central heating system

[croz1977]

Hello,

I have a one pipe central heating system with an 18 year old non-condensing boiler in my house. It all works fine however I am about to redecorate my enitre house including laying new solid wood floors throughout. So Im after some advice as to whether I should have a new two pipe system and condensing boiler installed or just save the money/hassle and leave the existing system in place. I ask as I have heard condensing boilers may not work on one pipe systems and eventually my old boiler will need replacing?

Many Thanks

Marc

 

[Armo74]

Your current system would have to be changed to a 2 pipe system anyway if your having a new boiler to comply with current regs.

 

[yerino]

Change to a two-pipe system.

 

[hansthebear]

Your current system would have to be changed to a 2 pipe system anyway if your having a new boiler to comply with current regs.

^ not true

 

[Whitespirit66]

Change the pipework anyway. No hurry to change the boiler, leave that until it goes bang. Boilers can be changed any time.

 

[middlesbrough]

Swap with a boiler with no sensor on the return ie baxi solo etc

 

[croz1977]

Yeah thats what i thought. one slight issue is that I already re-floored 3 of the upstairs bedrooms before i found out it was one pipe - so bloody annoying!

 

[mickyg]

if you can do it then do it. You dont have to have a 2 pipe system but it is beneficial

 

[dcawkwell]

Your current system would have to be changed to a 2 pipe system anyway if your having a new boiler to comply with current regs.

First I've heard of this?

 

[dcawkwell]

I would expect that the radiators are all old if your boiler is 18 years old
and you have a one pipe system.
Best to rip the lot out and install something efficient and modern.

 

[simond]

A one pipe system is very nearly as efficient as a two pipe.

If it is working OK with no problems you are not going to be any better off with two pipes under the floor. You must be the judge of how good the current system is.

Most modern condensers will work just fine on a one pipe, we've done plenty. If you go to a listed building with iron rads, who in their right mind would rip that out?

If you do fit a new boiler, one pipe systems can't be Powerflushed, so fit a decent dirt filter, such as the new uprated Magnabooster3.

 

[Dan Robinson]

Atmos/Intergas will do very nicely. It you go to a combi, you can weather comp the system nice and easily too.

 

[Armo74]

Apologies, i am not in the habit of giving out wrong information it was something i overheard in the plumbers merchants. Seems i shouldn't believe everything i hear

 

[croz1977]

Hmmm thanks all, opinion seems to be split on this one so guess ill toss a coin!

 

[Agile]

Many condensing boilers will work fine on a one pipe system.

However, there are two aspects you need to be aware of.

Old boilers are designed for a flow of 80 C whereas for a condensing boiler its 70 C although you can up that to 75 C without much loss of efficiency.

Condensing boilers are designed for a return 20 C below the flow. That means the return will be say 55 C and that means the last rads will be say 53 C instead of say 73 C.

Most houses with one pipes have undersized rads and I usually add a large central rad in say the hallway to increase the overall heat input to the house.

Another trick is to seperate the one pipe into two loops of one pipe.

Tony