Oil boiler CH pipe work questions?

[Cash4crash]

I am currently renovating a house which is running a vented back boiler system for the central heating and hot water. This is being removed and I want to have an oil Combi installed (professional install) but I want to do the pipe work with in the house my self.

There is already an oil tank installed so would purely be the pipe work and the boiler install it’s self.

Flow rate has been checked and is acceptable to run a Combi.

The plumbing system will consist of; 3 radiators down stairs and 3 upstairs (possibly 4). A hot and cold feed to the shower and bathroom sink, hot and cold feed to the kitchen sink and a cold water supply to the dish washer.

I’ve done basic plumbing before but never a full new install and I was just after some guidance on what I’m planning on doing mostly regarding the central heating system.

The boiler is going to be installed on the ground floor from there I want to run the flow and return in 22mm from the boiler directly into the ceiling. For the radiators upstairs from the 22mm I will run each rad individually on 15mm from a manifold.

For the radiators down stairs I want to T off of the upstairs 22mm run with another two pieces of 22mm which will go into the ground floor suspended floor and feed the 3 radiators down stairs in the same way individually from a manifold. The reason for going up and then down is due to the fact half the house is on flag stones and the other half is a suspended floor and the boiler will have to be installed on the side of the house with the flag stone floor. There is not really any way of running the pipe work from the boiler to the suspended floor with out crossing door ways or digging up the flagstones. If I do it this way it will mean I won’t have to run pieces of 15mm to each rad from upstairs saving on multiple pipe drops and making a nicer install.

For the hot and cold water I’m simply going to run the mains cold feed into the boiler in 15mm which will t off to the cold gaps and up stairs then the hot out will be on a T feeding upstairs and down stairs.

Will this system work and is it possible or will it cause me issues? Or is there a better way? and am I missing anything?

I know an expansion vessel will be required but the boiler I am planning on purchasing has one built in. All radiators will have TRVs and there will be a pressure relief and drain off installed to outside.

Thanks!

 

[terryplumb]

Sounds like a reasonable plan ,are you using copper pipes ?
How are pipes to all downstairs rads going to be routed ,surface mounted ?

 

[Cash4crash]

Sounds like a reasonable plan ,are you using copper pipes ?
How are pipes to all downstairs rads going to be routed ,surface mounted ?

Hi Terry,

Thanks for the reply all the pipe work to and from the boiler will be copper including the cold feed a few of the runs will be plastic due to ease of getting them under the floor.

Downstairs will be run under the suspended floor but to get to it I need to get into the upstairs first to be able to get past the door ways.

Would I have any issues with just TIng off the upstairs 22mm to feed downstairs ?

Thanks

 

[terryplumb]

Would I have any issues with just TIng off the upstairs 22mm to feed downstairs ?

Thanks

I wouldn't think so. Generally speaking ,pipe runs should be as short as possible ,but if it's not practical to take the direct route ,so be it.

 

[Cash4crash]

I wouldn't think so. Generally speaking ,pipe runs should be as short as possible ,but if it's not practical to take the direct route ,so be it.

Thanks mate, yeah I was worried going from down stairs to upstairs then back down would cause an issue but if not I’ll keep cracking on and get the rest in

With regards to everything else I’m planning on doing plumbing wise would that be okay?

 

[Stuart981]

I am currently renovating a house which is running a vented back boiler system for the central heating and hot water. This is being removed and I want to have an oil Combi installed (professional install) but I want to do the pipe work with in the house my self.

There is already an oil tank installed so would purely be the pipe work and the boiler install it’s self.

Flow rate has been checked and is acceptable to run a Combi.

The plumbing system will consist of; 3 radiators down stairs and 3 upstairs (possibly 4). A hot and cold feed to the shower and bathroom sink, hot and cold feed to the kitchen sink and a cold water supply to the dish washer.

I’ve done basic plumbing before but never a full new install and I was just after some guidance on what I’m planning on doing mostly regarding the central heating system.

The boiler is going to be installed on the ground floor from there I want to run the flow and return in 22mm from the boiler directly into the ceiling. For the radiators upstairs from the 22mm I will run each rad individually on 15mm from a manifold.

For the radiators down stairs I want to T off of the upstairs 22mm run with another two pieces of 22mm which will go into the ground floor suspended floor and feed the 3 radiators down stairs in the same way individually from a manifold. The reason for going up and then down is due to the fact half the house is on flag stones and the other half is a suspended floor and the boiler will have to be installed on the side of the house with the flag stone floor. There is not really any way of running the pipe work from the boiler to the suspended floor with out crossing door ways or digging up the flagstones. If I do it this way it will mean I won’t have to run pieces of 15mm to each rad from upstairs saving on multiple pipe drops and making a nicer install.

For the hot and cold water I’m simply going to run the mains cold feed into the boiler in 15mm which will t off to the cold gaps and up stairs then the hot out will be on a T feeding upstairs and down stairs.

Will this system work and is it possible or will it cause me issues? Or is there a better way? and am I missing anything?

I know an expansion vessel will be required but the boiler I am planning on purchasing has one built in. All radiators will have TRVs and there will be a pressure relief and drain off installed to outside.

 

[Stuart981]

Well you can spend a lot of dosh and get a super duper system and that's for sure. Whether it's value for money is another matterr. Depending where the back boiler is installed it might be possible to remove it and splice a free standing oil boiler into the existing pipework. Quite a few second hand boilers available due upgrade incentives.

 

[ericmark]

To my mind you're doing it the wrong way around, most DIY people can follow a plan and install pipework, the skill is designing the system to start with.

I say this, as I got it wrong. Moving from a modulating gas boiler to oil, I thought just a different fuel, so tried doing what worked so well with gas, but it didn't work well at all.

 

[Cash4crash]

Thanks for the reply mate, the current back boiler system really isn’t much use as it’s all run in microbore and is about 60 years old. A new install really is the only option

Well you can spend a lot of dosh and get a super duper system and that's for sure. Whether it's value for money is another matterr. Depending where the back boiler is installed it might be possible to remove it and splice a free standing oil boiler into the existing pipework. Quite a few second hand boilers available due upgrade incentives.

i Stuart

 

[Cash4crash]

To my mind you're doing it the wrong way around, most DIY people can follow a plan and install pipework, the skill is designing the system to start with.

I say this, as I got it wrong. Moving from a modulating gas boiler to oil, I thought just a different fuel, so tried doing what worked so well with gas, but it didn't work well at all.

Thanks for the reply. This is why I’ve asked if the system I am designing will work so as to be able to install it. I have a fairly decent understanding of how it should be done it’s just the fact I want to go upstairs then down where as most. Systems go from down to up and return

 

[Cash4crash]

I just want to double confirm that having the downstairs pipe work t out of the upstairs will not cause me any issues? Thanks

 

[terryplumb]

Boilers fitted on the ground floor very often have flow and return pipework run upwards ,and back down to ground floor rads , particularly when ground floors are concrete .

 

[Exedon]

What your suggesting is called drop pipe very common system.
Done many hundreds of houses like it (sometime new build contractors) mostly using 10mm back box system but of course 15mm works as well!.

 

[Cash4crash]

Thanks everyone