
A heat pump estimate before anyone books a survey
A customer fills in your enquiry form. Payaca pulls the EPC, runs the heat loss, sizes the heat pump and cylinder from your own appliance list, takes off the Boiler Upgrade Scheme grant and drafts an indicative estimate with the bill savings on it, ready for you to check and send.

Flow is the fast heat pump estimate in Payaca. It is in limited release for UK accounts.
It is not a calculator on a website. The enquiry, the estimate, the survey, the proposal, the materials and the MCS paperwork sit on the same project, so the number the customer saw is where the job starts.
Related reading
From enquiry to estimate
Put a heat pump enquiry form on your website. The customer enters their address and picks their EPC from the EPC register for England and Wales, and the property details fill themselves in. If there is no EPC, or theirs is out of date, they answer a few questions about the property type, age, size, bedrooms and current heating instead.
The enquiry creates the project in the right pipeline and a draft estimate on it. For a project you created yourself, enter the same property details on the project and create the estimate from there.
Heat loss, from the EPC or the customer's answers
Payaca works out the peak heat loss of the property. Where the EPC or the customer gives annual energy use and the heating is gas, oil or LPG, the heat loss comes from real fuel consumption. Otherwise it comes from the property type, age and floor area.
The coldest expected outdoor temperature comes from the postcode area. From the peak heat loss Payaca gives a heat pump size range, and from the number of bedrooms a minimum cylinder size, all shown on the project's property tab.

Sized from the appliances you fit
Set up the heat pumps and cylinders you sell as preferred appliances, each linked to the items you charge for it. Flow keeps the heat pumps that can meet the peak heat loss, recommends the best match and picks a cylinder big enough for the household, unless the heat pump has one built in.
The appliances' items go onto the estimate at your prices, along with the default items you always include, such as installation, commissioning and the survey. Check it, change anything you want, and send it.
The grant taken off, the savings shown
If your account is onboarded to the Boiler Upgrade Scheme, the BUS grant is added to every new heat pump estimate. It shows as a named deduction above the total payable, so the customer sees the number they would actually pay.
The estimate also shows the projected annual bill savings against the customer's current heating, worked out from the heat pump's seasonal performance with a real world adjustment, under different electricity tariffs. When there are savings, it shows a payback period too.

The fast estimate, not the design
Flow gives the customer a real number while they are still interested. It is the fast estimate, not room by room heat loss. Your design tool still does that part, and the Heatpunk and Spruce integrations are unchanged.
When the customer is happy, convert the estimate to a proposal on the same project and carry on from the survey. Nothing is sent to the customer until a person on your team sends it.
What's included
What Flow does, from the enquiry form to the estimate.
From the enquiry form
A customer fills in your heat pump enquiry form and picks their EPC, or answers a few questions about the property. The project and a draft estimate are created from their answers.
Heat loss from the EPC
Payaca pulls the EPC and works out the peak heat loss against the coldest expected temperature for the postcode, from real fuel use where the data has it.
Sized from your appliance list
The heat pump and cylinder are matched from the appliances you actually fit, sized against the heat loss and the number of bedrooms, and priced from your own items.
The BUS grant taken off
If your account is onboarded to the Boiler Upgrade Scheme, the grant is added to every new heat pump estimate and shown as a deduction above the total payable.
Bill savings on the estimate
The customer sees the estimated heat loss and the projected annual bill savings against their current heating, with a payback period when there are savings.
The fast estimate
Flow gives the customer an indicative number before the survey. It is not room by room heat loss, and your design tool still does that part.
Flow is in limited release
It's a limited release. Book a call and we'll switch it on.
Built for
Frequently asked questions
- What is Flow?
- Flow is the fast heat pump estimate in Payaca. A customer fills in your enquiry form, Payaca pulls the EPC, runs the heat loss, sizes the heat pump and cylinder from your own appliance list and takes off the Boiler Upgrade Scheme grant, so you can send an indicative estimate before a survey is booked.
- Can I use Flow now?
- Flow is in limited release for UK accounts. Book a call and we'll switch it on for your account.
- Where does the heat loss figure come from?
- From the EPC where there is one, or from the property details the customer gives on the enquiry form or you enter on the project. Where annual energy use is known and the heating is gas, oil or LPG, it is worked out from real fuel consumption. Otherwise it comes from the property type, age and floor area, against the coldest expected temperature for the postcode area.
- What if the property has no EPC?
- Properties without an EPC, including homes in Scotland, use the property details the customer enters on the enquiry form or that you enter on the project yourself. The heat loss is worked out from the property type, age, floor area and bedrooms instead.
- How are the heat pump and cylinder chosen?
- From the heat pumps and cylinders you have set up as preferred appliances. Flow keeps the heat pumps that can meet the property's peak heat loss, recommends the best match on the price of their linked items, and picks a cylinder that meets the minimum size for the number of bedrooms.
- How is the Boiler Upgrade Scheme grant handled?
- If your account is onboarded to the Boiler Upgrade Scheme, the BUS grant is added to every new heat pump estimate. It deducts from the gross total to give the total payable, and you can remove it on a draft estimate where it does not apply.
- Does Flow replace room by room heat loss?
- No. Flow is the fast estimate that comes before the survey. Room by room heat loss is still done in your design tool, and the Heatpunk and Spruce integrations keep working as they did.
- Can I offer the customer more than one option?
- Yes. A project can hold several estimates at once. Duplicate the estimate and swap the heat pump to offer a larger or a smaller system side by side.
- Does the estimate go to the customer automatically?
- No. The enquiry creates a draft. Someone on your team checks it and sends it, and the customer opens it in your customer portal.
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