Advice on new Extension DHW please

[Masterpop]

I would like some ideas on possible designs for our house please.

We currently have a 1 bathroom detached house running off an Vaillant Ecotec 937 combi. When the dishwasher is running the shower is dreadful.

We are going to do an extension which will add 2 more bathrooms... Clearly the combi can't handle 3 bathrooms...

So what would people suggest?

1. Can I use the combi boiler to heat an indirect unvented cylinder?

Any thoughts welcome

Thank you

 

[TCCHeating]

1. Can I use the combi boiler to heat an indirect unvented cylinder?

Yes.

 

[mfarrow]

You mean like I have? Yes, a combi boiler is just a standard boiler on steroids.

Just disconnect the cold in and hot out and never have to worry about diverter valves or diaphragms again.

 

[muggles]

1. Can I use the combi boiler to heat an indirect unvented cylinder?

Yes you can, very easily, but if your shower flow rate drops dramatically when the dishwasher is on then I'd suggest you have bigger things to think about, IE that your incoming mains isn't capable of supplying enough water to run an unvented cylinder, or three bathrooms. Dishwashers are almost all cold-fill only, so the hot water performance of your combi is irrelevant to the change in shower performance when the dishwasher runs. You'll need to consider upgrading the incoming mains from the street into your house as part of your extension works, and also find out whether this upgrade is likely to have any significant effect on flow rate. What is your static pressure (IE the pressure with no water flowing)? You can find this out by attaching a water pressure gauge to your outside tap and turning the tap on, making sure that no water is being drawn anywhere else. If pressure is high but flow is low, you've got a chance of sorting it. If static pressure is low, you're looking at putting in loft tanks to store water, and a pump to supply the unvented cylinders