Worcester Greenstar Boiler issue

v10

MiniGolf wrote: »

On a WB boiler it should be 3/4" all the way. Due to internal pipe work on the gas train in a WB you can have as low as 16.5mb at the test nipple on full fire.

Is 3/4" all the way normal for most boilers ? or are WB boilers different in this respect ? I only ask because the plumbing was already 1st fixed before I insisted on a WB boiler, so the plumber could argue that he installed 15mm not knowing it was to be a WB boiler ..

Also the boiler hasn't stopped since I shifted the white pipe down a bit so that the condense water doesn't build up, but some responses here have me concerned that the gas pressure is also too low ? What harm is this and what damage is it likely to cause ? .. changing the copper to 3/4 at this stage would involve digging up my new utility room :eek:

shane0007

3/4" should always be brought as close as is possible to the boiler. Depending on the boiler output, some require 1".
Most boiler connections are 1/2" but it should be 3/4" to that point.

v10

shane0007 wrote: »

3/4" should always be brought as close as is possible to the boiler. Depending on the boiler output, some require 1".
Most boiler connections are 1/2" but it should be 3/4" to that point.

and what harm if it isn't ?

shane0007

v10 wrote: »

and what harm if it isn't ?

Boiler will not be a 30kw when in high fire as it won't be receiving enough gas to produce 30kw.
Secondly, when in high fire, the fan speed will be set to 30kw so it will be over-aired so it can potentially affect combustion.
It will depend on the actual working pressure of the boiler compared to the working pressure at the meter.

v10

shane0007 wrote: »

Boiler will not be a 30kw when in high fire as it won't be receiving enough gas to produce 30kw.
Secondly, when in high fire, the fan speed will be set to 30kw so it will be over-aired so it can potentially affect combustion.
It will depend on the actual working pressure of the boiler compared to the working pressure at the meter.

Great, thanks for your answers, appreciate it. Just trying to educate myself a bit before I meet with the plumber !:D

smartbodydublin

I'm looking for quotes on a new gas boiler installation. There's an existing open fire backboiler heating system. Am looking at either keeping the hot water storage tank or going for a combi boiler. I have an electric mains fed shower and don't use much hot water.

Based on threads I've read on Boards.ie I'm wondering who to trust with with an install. Not sure if registered installers are all up too the grade. Amn't in a hurry at this point.

Recommendations welcomed from you helpful bunch as you seem to be conversant with installation specifications and implementation. I did cop your installers.

Small 3 bedroom corporation build circa 1940s. Dublin 12. Please pm numbers of competent installers near by. Thanks

shane0007

Are you wishing to keep the back boiler or de-commission it?

smartbodydublin

Thanks for getting back to me Shane. When you've time you might indulge long post and some of my confusion.

Any option I'm looking at would have the old boiler decommissioned or removed completely.

I'm not sure how to weight up the cost benefit of different options.

I started by wanting to get a back boiler stove plumbed into pipe work of old back boiler after it is removed. We loved the open fire but with colder weather more frequent I wanted to up the heat a bit and figured a stove boiler was way to go and much more efficient. A friend got me looking at the long term benefit of gas c.h.

I'm now strongly looking at gas combi for radiators circuit and hot water on tap.

Then looking to (maybe) fit 5kw inset or stand out non-boiler stove, as I understand I'd be ok up to 5kw without increased airflow into room.

Hope was to use gas c.h. for few hours and then turn off and use stove in living room with one door open to stairs to keep chill at bay. For the time being if I go gas c.h. may just decommission old boiler and stuff/seal flu.

We use/need very little on tap hot water so not sure if I'm served better with combi or system boiler with valve/zone control for storage tank. I'm simply not sure in the long run which is less expensive to live with and maintain. I'd guess the combi saves me in the short run but then have to pay more as more parts to wear and more to service.

But I'd be using the on tap heater very little so that section/part of boiler would likely last long time.?

Can on-tap heater section of combi boiler be switched off to stop wasteful use of water and gas if needs be? I fear what bills may look like in a few years.
I think I saw a knob on an Ideal combi model, that had option to turn off tap feed. Don't shoot me if I'm way off with how they may/need function. I only ever done basic diy gravity tank, pump swaps on old system. Am clueless on gas boiler options and functions.

Professional advice welcome. This is big decision and am slow to move as wont be able to change anything with heating system again in future.

shane0007

A combi would suit a low HW demand. You don't need to fit anything special to stop it using the combi side, just don't open a hot tap & it won't come on.

You could use a gas stove. I recently fitted a Valor gas stove, 89% efficient. Brilliant heat from it.

v10

Well lads this is how my plumber fixed it.

Thank god all this mess is hidden in a cupboard.