New boiler output pressure (bar)?

[Londoner]

I'm thinking of changing our old conventional boiler for a combi (Worcester Bosch), but right now we use a Hansgrohe Raindance shower with a Salamander pump attached.

My hope was the switching to a combi would mean we could lose the pump and just run off the combi pressure. However I'm finding it hard to find out exactly what pressure Worcester Bosch boilers output. Everything is in kW and l/m. Am I barking up the wrong tree is trying to look for a pressure/bar rating?

 

[Dan Robinson]

It is the pressure of your water main that is important.

Then you need to measure the flow rate your supply provides and match the boiler to that (and your houses' heating needs.

I doubt you'll be happy with the shower performance off a combi boiler.

 

[Londoner]

That's what I was afraid of. Is it fairly common for people to have a shower pump running off a combi system?

 

[doitall]

Very unlikely you can have a pump with a combi, unless you pump the inlet from a break tank, and even then you are restricted to what the boiler can produce.

 

[Londoner]

So where does that leave me.... If I switch to a combi, I lose the ability to have a shower pump and have to put with a much weaker shower?

 

[Dan Robinson]

You need to find out what your water supply is capable of first.

If it is decent then you can look at an unvented cylinder.

Search the forum. This topic has been done to death.

 

[Londoner]

I didn't want to get into unvented systems because of the cost. The biggest reason for going combi was the fact it's a cheaper option, as well as freeing up space from losing the storage tanks.

 

[Dan Robinson]

Champagne ideas.

Beer money.

 

[ianmcd]

It might be your best option to get a combi but as you have already been advised you need to check the dynamic flow rate of your existing water supply, turn a cold tap on that is mains fed and time how long it takes to fill a container that you know the volume of , for simplicity if the container holds 10L and takes 1 min to fill then your flow rate is 10L/min, once you know what it is come back for more advice

 

[muggles]

Champagne ideas.

Beer money.

Indeed...

 

[Tipper]

.......I doubt you'll be happy with the shower performance off a combi boiler.

Why do you say that?

I've got 4 properties all with Vaillant combi boilers and everybody who uses the showers praises them!

 

[Dan Robinson]

It depends on the shower heads.

The OP needs to measure things - as told to several times.

The last Raindance I fitted had a monster head and no combi would give it a decent performance.

Perhaps they have more efficient ones now?

Overpriced kit IMO; but easy to install.

 

[Agile]

Is that your shower Dan?

 

[Dan Robinson]

No - I have some daft thing from Porcenalosa. Not my choice - already here.

this was for a customer with an odd shaped bathroom - so they had a very very expensive Japanese bath fitted that consumed a lot of water - deep square thing.

 

[Dan Robinson]

Here you go: