Grün Engineering

What we need to price your flue job

Read time 4 min

You don’t need a full design to get a price. This guide covers the seven bits of information that let us price a flue job, why each one matters, and what to do if you only have some of them.

Short answer

Drawings, photos or a rough outline is enough to start. The price gets firmer the more of these you can tell us: appliance type and number, output, outlet size, rough route lengths, new flue or existing chimney, where it comes out, and site location. If something is missing, we price from what you have or arrange a survey.

Start with what you have

Send whatever you’ve got. A drawing, a few photos from your phone or a description in an email all work. We’d rather start with something rough than wait for a full set of drawings.

We normally send a price within 24 hours of getting drawings or survey information.

The seven things that set the price

  1. Appliance type and numberBoiler, generator, water heater or CHP, and how many. Different appliances need different flue systems. The number tells us whether each one gets its own flue or they join into a shared header.
  2. OutputIn kW for boilers or kVA for generators. It tells us how much the flue has to carry, and it goes into the sizing calculations.
  3. Spigot or outlet sizeThe diameter where the flue connects to the appliance. The first piece of the flue has to fit it.
  4. Rough route lengthsRoughly how far the flue runs up and how far it runs across. A flue is mostly straight lengths, bends and supports, so the lengths drive the quantities. A rough figure is fine for a price.
  5. New flue or existing chimneyWhether there’s a chimney there now that could be used. An existing chimney is often lined. Otherwise it’s a new stack. Photos of what’s there help a lot. Can my old chimney be used?
  6. Where it comes outThrough the roof, out of a wall or at the top of a chimney. This changes the parts at the top end and the route the flue takes to get there.
  7. Site locationTown or postcode. We work across the UK and Ireland, and the location helps us plan travel and deliveries.

Diagram

Where each piece of information comes from

A simple flue run from the appliance to the terminal. Each number is one of the seven things above.

Drawing of two boilers in a plant room joining into a shared header, which runs across to a riser that goes up through the roof to a terminal. Seven numbered points: 1 appliance type and number, 2 output, 3 spigot size, 4 route lengths across and up, 5 new flue or existing chimney, 6 where it comes out, 7 site location.
  1. Appliance type and numberFrom the appliance or plant schedule.
  2. Output in kW or kVAFrom the schedule or the appliance nameplate.
  3. Spigot or outlet sizeFrom the appliance data sheet, or measured.
  4. Rough lengths, up and acrossFrom the drawings, or a tape measure on site.
  5. New flue or existing chimneyFrom what is there now. Photos help.
  6. Where it comes outRoof, wall or chimney top, from the drawings or photos.
  7. Site locationTown or postcode.
Two boilers into a shared header, up a riser and out through the roof. Your job may look different, but the same seven things apply.
Stainless boiler flue header with tees off each boiler and a riser in a hospital plantroom
Reading Hospital, Reading, boiler flue header

If you don’t have it all

Send what you have and tell us what’s missing. We can price from part of the list, or arrange a survey to fill the gaps.

What happens on a flue survey

About the rules

You don’t need to work out flue sizes or heights yourself. We do the calculations and check the design against the current regulations.

Design and calculations

What happens next

  1. Your enquiry is registeredThe same day, with a job reference.
  2. We send a priceNormally within 24 hours of getting drawings or survey information.
  3. You order, we set the job upWe acknowledge the order, set up the job and share a project folder with you.

Common questions

Asked most about pricing.

Anything else, call 01395 201950 or email sales@gruneng.com.

  • Do I need full drawings to get a price?

    No. Drawings, photos or an outline is enough to start. We price from that or arrange a survey.

  • How quickly will I get a price?

    Normally within 24 hours of getting drawings or survey information.

  • Do you do supply only?

    Yes. We do supply only, install only, or supply and install.

  • Is there a minimum job size?

    No. We do commercial and industrial work only, with no minimum job size. We don’t do domestic work.

  • Who works out the flue size?

    We do. We do the calculations and check the design against the current regulations.

Related

Send drawings. Get a price.

Send what you have. A price normally comes back within 24 hours.

Get a price Call