Options for second bathroom

---lee---

I'm having an extension built which includes a new bathroom. We have a combi boilers and a combiforce shower which works well with the current setup.

Builder is suggesting I go with an electric shower in the extension. I'm not keen as I belive them to be a poor compromise.

What are my options?

1. Electric shower. Pros. Easy and cheap. Cons. Does the mains support sufficient flow for combi and electric shower. I dislike electric showers.
2. Add unvented cylinder. Pros. Lots of stored hot water on demand under preassure. Cons. As per pros + more complicated system, heat loss etc. If only plumbed to the new bathroom, I'm guessing this is the only option that guarantees good simultaneous showers in both bathrooms.
3. Add second combi. Pros. Good showers at both locations. Double fill speed of Bath if plumbed correctly. Cons
Can water flow and gas supply cope. Additional servicing costs.

Thoughts and experiences please.

glasgowdan

If the combi is a decent size then just get a thermostatic shower.

---lee---

glasgowdan wrote: »

If the combi is a decent size then just get a thermostatic shower.

It's a Main Eco, 30 kW model. I already have a balanced shower in the main bathroom.

Doozergirl

Are you sure it isn't capable of doing the job? You've only got one bathroom at the moment?

Run it through the Worcester Bosch web page which recommends a size of boiler before you make a decision on changing it or adding another one.

I don't pretend to be an expert on plumbing but it makes reasonable sense that one correctly sized boiler is going to be more cost efficient than two which will have more capacity than is needed.

System

How likely is it that both will be running at the same time?

---lee---

Doozergirl wrote: »

Are you sure it isn't capable of doing the job? You've only got one bathroom at the moment?

I'm reasonably confident. Running the hot tap whilst the shower is running virtually stops it. Running a cold tap reduces it's flow but it's still ok.

Run it through the Worcester Bosch web page which recommends a size of boiler before you make a decision on changing it or adding another one.

Can't seem to find that page.

I don't pretend to be an expert on plumbing but it makes reasonable sense that one correctly sized boiler is going to be more cost efficient than two which will have more capacity than is needed.

I don't think physics or technology have moved on that much since my last boiler purchase. i'm happy to be wrong though.

---lee---

the_r_sole wrote: »

How likely is it that both will be running at the same time?

Without planning, it's going to happen with reasonable frequency as it's me vs three females, two are adults and the other a teenager. We could plan around it but if the cost is model, I would rather have the best of both worlds.

Another consideration is that I want quite a large bath, so filling time is going to be an issue.