Combi & showers

[kathb0110]

Hi
Just had a chap round to do a "technical survey" as I qualify for the boiler replacement scheme. Unfortunately he was like a whirling dervish in and out in 7 mins!
He filled in lots of paperwork - I had to sign, but haven't got a copy.
I am going from hw tank to a combi and he has told me my showers won't work. I have a Mira Verve and a Grohtherm 1000, both of which say they work with combi boilers. The quick bit I saw of his paperwork said I would be getting a Baxi boiler and new TRV's.
I am concerned why he thinks my showers won't work, when the documents say they will - and by the fact he had never heard of Grohe......He also said I can only use one hw tap at once.....
His company aren't filling me with confidence. Even if it is on the boiler scheme I don't want to be saddled with something unsuitable!

Any advice on whether this new combi will do the job and whether the showers will work please?

 

[Tipper]

Presumably both your existing HW and CW systems is all low pressure from the tank in the loft?

If so then it's all low pressure and the combi will be providing high presure water to the hot taps. This isn't compatible with the low pressure cold water.

You will need to upgrade the whole water system, both hot and cold to high pressure direct off the mains, via the combi in the case of the hot water.

Hope that clears it up.

 

[kathb0110]

hmmmmm
I think I'm with you.....

My mains comes up in the kitchen and the boiler is in the garage - not a direct route. Presumably this means it will be a major job to upgrade to a high pressure system off the mains?

May be I need to stick to the system I have and put pumps on the showers....

What do you think?

 

[Galoka]

Well, first off don't feel you have to go ahead with anything unless you are happy you understand everything. I suspect these schemes often attract the chuck it in quick and take the money merchants. At the very least I'd be on the phone asking them to explain the things he said.

You need to understand the benefits and limitations - of a combi - Yes, you current shower units should operate fine in principle - but how are they currently fed? direct from loft and HW tank, pumped or not?

The water won't run out but you will only be able to run one shower at a time, and turning on more than one tap will tend to lead to poor flow from both, bath filling takes for ever.

 

[kathb0110]

Thank you.

I will have a chat with npower. I have a gas heating engineer I have used many times before and would trust him, I know he does do this scheme, but don't know whether npower would let him/me if they only use certain firms.

If, as seems likely my cold water runs through the loft tanks:

a. how does my boiler get the water now - is it from the loft?
b. how do I tell?
c. how much of a job is it changing the plumbing to go straight to the boiler in the garage from the mains?

Many thanks for all your help

 

[kathb0110]

...next daft question....

Presumably my cold water goes from the mains direct to the water tanks, where it then goes to the boiler, to the hot water tank, to the shower.

The "technical survey guy" wants to drill a hole through to the downstairs loo, to pick up a cold water feed. Presumably the water will then go from there, in to the boiler and then upstairs...and then they will take out all the hot water tank gubbings and connect to the hot water feed in the old airing cupboard area.

So the cold water will stay as it is, from the mains, to the tanks, to the shower etc.

For the showers to work off mains pressure, can't they just disconnect the cold from the water tanks and bypass them? Will that make it mains pressure? Or is that me thinking it would be too easy.....hmmm

 

[kathb0110]

All sorted!

Thanks for your help. I do have mains pressure on the upstairs cold so that's a bonus.
I have spoken to the heating engineer who I trust, so I can now cancel npower's team and go with the trusty one

So am now a very happy bunny