Combi Boiler Pressure Test

bob2oo7

Hey guys

Builder and plumber say my house is ideal for a combi boiler

Pressure test shows 1 Barr

Small house, 1 bathroom uptairs, one shows, tiny barroom under stairs

They are pushing for this and I want to make sure my shower doesn't end up being a trickle

Is 1 Barr enough?

Dtp1979

bob2oo7 wrote: »

Hey guys

Builder and plumber say my house is ideal for a combi boiler

Pressure test shows 1 Barr

Small house, 1 bathroom uptairs, one shows, tiny barroom under stairs

They are pushing for this and I want to make sure my shower doesn't end up being a trickle

Is 1 Barr enough?

Mains water doesn't suit combis over here cause it's crap and inconsistent. Unlike England. If you want a combi, install a water tank and have a booster pump feeding your water services incl boiler. That way you'll have consistent good pressure.

bob2oo7

Dtp1979 wrote: »

Mains water doesn't suit combis over here cause it's crap and inconsistent. Unlike England. If you want a combi, install a water tank and have a booster pump feeding your water services incl boiler. That way you'll have consistent good pressure.

Thanks

But if you live in a area where the mains and pressure is ok? Is a combi the way to go?

Dtp1979

bob2oo7 wrote: »

Thanks

But if you live in a area where the mains and pressure is ok? Is a combi the way to go?

Yes. But in ireland it's not. Plus you've water hardness to take into account. 1 bar pressure is easy to get. It's more important to have excellent flow rates which is where Irish water fails.
Are you so confident in your mains water that, if you turn on every hot and cold tap in your house that your going to have a good fast equal flow from them all?? If the answer is no, then install a tank and pump

bob2oo7

Dtp1979 wrote: »

Yes. But in ireland it's not. Plus you've water hardness to take into account. 1 bar pressure is easy to get. It's more important to have excellent flow rates which is where Irish water fails.
Are you so confident in your mains water that, if you turn on every hot and cold tap in your house that your going to have a good fast equal flow from them all?? If the answer is no, then install a tank and pump

In what situation would every tap etc. be turned on?

The shower will be on mostly in the morning before work

Maybe a bath 2/3 times a week for kids

Dish washer and washing machine overnight when everyone is asleep

Dtp1979

bob2oo7 wrote: »

In what situation would every tap etc. be turned on?

The shower will be on mostly in the morning before work

Maybe a bath 2/3 times a week for kids

Dish washer and washing machine overnight when everyone is asleep

You can't have that mindset when designing a system. The system has to be able to cater for it being used at the max. What if you're having a shower, your wife flushes the toilet and at the same time somebody is in the kitchen turning on the sink tap to fill a glass of water? A highly likely situation.

bob2oo7

Dtp1979 wrote: »

You can't have that mindset when designing a system. The system has to be able to cater for it being used at the max. What if you're having a shower, your wife flushes the toilet and at the same time somebody is in the kitchen turning on the sink tap to fill a glass of water? A highly likely situation.

Understood

How do we know if all that can be achieved?

We are relying on the builder and plumber to guarantee that it will be

We were never even going with this until they both said it was an ideal house for it

Dtp1979

bob2oo7 wrote: »

Understood

How do we know if all that can be achieved?

We are relying on the builder and plumber to guarantee that it will be

We were never even going with this until they both said it was an ideal house for it

To me, it feels like they're trying to cut corners of there avoiding a water tank and booster pump.
Your incoming mains is 1/2" pipe. It's just not able to supply everything at once. Whereas a booster pump will have an outlet of 1".

Wearb

Is it a new house? Does it have a hotpress? Not many plumbers recommend combi's in this country.

bob2oo7

Wearb wrote: »

Is it a new house? Does it have a hotpress? Not many plumbers recommend combi's in this country.

Old house but it's been gutted

Hot press is there but old tank is gone

Also... Is it normal for a non RGI plumber to do an install but then get it checked and certified by an RGI registered plumber??

Dtp1979

bob2oo7 wrote: »

Old house but it's been gutted

Hot press is there but old tank is gone

Also... Is it normal for a non RGI plumber to do an install but then get it checked and certified by an RGI registered plumber??

Absolutely not. It's illegal, dangerous and in no way should you let this cowboy continue to work in your house. He's putting you and your family's lives at risk

0e1

Depends on your location .Where is the pressure gauge reading 1bar you mentioned ? Some areas do require a tank and booster pump . In my area the mains is more than sufficient for a combi boiler .In a small house with correct mains pressure ,I would also recommend a Combi. Do not leave any non RGI near your gas appliances or pipework .

rightjob!

You cannot go straight into the combi with the mains.

Your asking for trouble from the get go,you said its a old house thats gutted if your spending money do it properly.
Fitting a pump boosting into your combi is the only way you can guarantee that your pressure will be good all year round.

There is too many factors otherwise,plus its against regs too.

bob2oo7

rightjob! wrote: »

You cannot go straight into the combi with the mains.

Your asking for trouble from the get go,you said its a old house thats gutted if your spending money do it properly.
Fitting a pump boosting into your combi is the only way you can guarantee that your pressure will be good all year round.

There is too many factors otherwise,plus its against regs too.

Thanks for all the input so far

I'm gonna word this a different way

If it was you, you had a house gutted. Hot water cylinder already taken out, tank still in the attic, house is 90 square metres, 1 shower, 1 bath, 2 toilets and 3 sinks

House will be connected to Gas, was previously oil

The whole house is being re plumbed and re wired

What would you do?

Dtp1979

bob2oo7 wrote: »

Thanks for all the input so far

I'm gonna word this a different way

If it was you, you had a house gutted. Hot water cylinder already taken out, tank still in the attic, house is 90 square metres, 1 shower, 1 bath, 2 toilets and 3 sinks

House will be connected to Gas, was previously oil

The whole house is being re plumbed and re wired

What would you do?

Neither of us advised you against going with a combi. We advised you to do it properly and fit a tank and booster pump, and not use mains directly
And by the way, as I said earlier, get rid of the cowboy whose non Rgi but willing to work on gas

bob2oo7

Dtp1979 wrote: »

Neither of us advised you against going with a combi. We advised you to do it properly and fit a tank and booster pump, and not use mains directly
And by the way, as I said earlier, get rid of the cowboy whose non Rgi but willing to work on gas

No no, I get that. Thanks

I just want to get my head around it

So...

The water tank will feed toilets, wash basins and shower/bath?

This will flow through the pump and boiler to provide instant and pressurised hot water on demand

The kitchen sink will be the only tap working off the mains? But again will go through the boiler to provide hot water on demand?

Where does the dishwasher and washing machine feed from?

Based on this, the water tank and pump should be beside each other and in the attic?

Dtp1979

bob2oo7 wrote: »

No no, I get that. Thanks

I just want to get my head around it

So...

The water tank will feed toilets, wash basins and shower/bath?

This will flow through the pump and boiler to provide instant and pressurised hot water on demand

The kitchen sink will be the only tap working off the mains? But again will go through the boiler to provide hot water on demand?

Where does the dishwasher and washing machine feed from?

Based on this, the water tank and pump should be beside each other and in the attic?

The tank in the attic will feed the toilets directly if possible. This way it shortens the amount of time the pump runs for, plus you won't hear the pump at 2am if you flush it.
Mains will go to kitchen sink, dishwasher, washing machine and attic tank only. Your pumped water will go to the boiler, the basins, shower and bath. If your putting the pump in the attic, use flexi hoses off it and suspend it off the floor using rope. This reduces the noise level.
If you have hard water then make sure a water Softner is fitted because line scale will wreck your shiny new combi boiler.

bob2oo7

Dtp1979 wrote: »

The tank in the attic will feed the toilets directly if possible. This way it shortens the amount of time the pump runs for, plus you won't hear the pump at 2am if you flush it.
Mains will go to kitchen sink, dishwasher, washing machine and attic tank only. Your pumped water will go to the boiler, the basins, shower and bath. If your putting the pump in the attic, use flexi hoses off it and suspend it off the floor using rope. This reduces the noise level.
If you have hard water then make sure a water Softner is fitted because line scale will wreck your shiny new combi boiler.

Can the pump go outside then? So when you want hot water, the water leaves the tank, goes to the pump, the to the boiler and out the tap?

Same process in the kitchen except from the mains?

Dtp1979

bob2oo7 wrote: »

Can the pump go outside then? So when you want hot water, the water leaves the tank, goes to the pump, the to the boiler and out the tap?

Same process in the kitchen except from the mains?

Yes it can go outside once it has no chance of freezing. Make sure the same pump is supplying cold to the same shower if it's a mixer shower because you'll want equal pressure on both sides