TECHNICAL SUPPORT
– INSTALLATION GUIDE

How to install a single pipe fuel supply system, points to consider

About Hounsfield monoblock oil filter/ fire valve kits

We’ve drawn on our experience to carefully select the components for our monoblock oil filter/fire valve assembly.

– The fire valve (Made in Britain) uses oil as the expansion medium; being more stable than gas commonly used in other fire valves, it’s not susceptible to nuisance trip-outs. It has integral compression fittings.

– The oil filter has a bowl with a wide flange-to-flange seal face rather than the edge of a pressed steel filter bowl found on commonly used oil filters. It has stainless steel fittings.

– Crucially, the number of fittings and joints is reduced compared to installing individual components, an important consideration when installing an oil line.

Oil line installation, these points apply to our wall-mounted boilers: they are relevant to all installations

1. Ideally, the only pipe connections above the “minimum oil level” in the fuel tank should be the flexible hose and copper oil line onto the bulkhead connector inside the boiler casing (wall-mounted boilers).

2. Use pipe benders rather than additional compression fittings for the length of the fuel line.

3. Always use oil line inserts Pt.no. BS0008

4. Install the oil filter assembly just above ground level, before the vertical rise of the oil line to the boiler; this maintains a head of oil pressure on the non-return valve and keeps joints that could potentially draw in air below minimum oil level.

Boiler installation height/ suction height

The Danfoss fuel pump we specify is designed to lift oil up to 4 metres; for wall mounted boilers we recommend a maximum installation height of 2 metres, the overriding consideration being to provide safe access for servicing the boiler.

Fuel pump failure

Fuel pump failure due to fuel contamination is common and expensive to rectify; it’s directly related to the difficulty of removing debris that accumulates at the bottom of plastic oil tanks, and there is no easy way to remove it.

In contrast, steel oil tanks are fitted with a sludge valve to facilitate sludge drainage at service intervals. We recommend steel oil tanks. They’re infinitely recyclable and do not suffer catastrophic failure from splitting, as plastic tanks do.

Install a good quality oil filter near the tank

Given the above, we recommend installing a good-quality paper element filter (Pt.no. BS002-A) near the tank as a first line of defence; gauze filters/strainers commonly used in tank filters do not provide adequate filtration and will allow contamination to pass through. The particle size/filtration rate of gauze filters is up to 120 microns; a paper element filter is 10 microns.

A large paper element filter bowl also provides important visual information for analysing contaminated fuel; strainers and spin-on enclosed cartridge filters don’t provide that.

Deaerators such as Tigerloops not required

Deaerators are not required with the Danfoss fuel pump we specify, saving on installation costs and associated ongoing maintainance. For technical reasons they are required with Riello fuel pumps. Refer to the technical explanation on our website support page, “Tigerloops not required pdf”

Hounsfield Boilers are supplied with oil filter/ fire valve kits.

OPTIONS: For kitchen models specify capillary length required, 3 to 35 meter lengths available.