Blog / wet underfloor heating

Whilst not the proverbial ‘rocket science’, specifying an underfloor heating (UFH) system correctly is important to ensure a number of things:

The following information aims to debunk 8 of the most common myths that surround the installation and running of underfloor heating systems.

When fitting underfloor heating the floor surface temperature will vary. In this article to go over some statistics for your benefit.

1. If you have a fault once the system is up and running, the first thing to check is the flow rate in the flow meters. Make sure they are set between 1.5L/min and 2L/min for boiler use and 1L/min for heat pump use. If there is no reading (the red indicator is at the top) nothing is flowing around the loop.2. Then take off your actuator heads, if you then get a flow or your system then works you know it is an electrical problem. If after taking all the actuators off you still have problems then it will be a flow fault

We answer your questions about laying underfloor heating onto existing floors.

There are two types of underfloor heating: gas-powered (wet) underfloor heating and electric underfloor heating.  In wet underfloor heating systems, heat is distributed around the house via thin pipes laid under the floor. These pipes carry hot water around the home so that it can release its heat through the floor and therefore warm the rooms where the underfloor heating system is installed. The water is heated in the main boiler of the home. In cases where the boiler supplying hot water for the household is gas powered (as is the case in most UK households) this type of heating system is known as wet underfloor heating. An electric underfloor heating system, on the other hand, uses electric wires fitted beneath the floor to provide heat. When an electric current is passed through the wires, they become hot and that heat is transferred through the floor to the room above.

The use of aluminium ‘spreader plates’ is common in installing water underfloor heating to joisted floors.There are pros and cons of the use of spreader plates that should be considered for water underfloor heating:Pros1.    Easy to install for the novice installer as they set the pipe spacing2.    Lightweight – where biscuit mix can’t be used3.    Clean installation – less mess than biscuit mix4.    Quicker – generally faster to install than biscuit mix5.    Spread the heat evenly when used with insulation alone

A test is performed at a pressure of 5 bar before flooring, screed or biscuit mix is laid to check for leaks and ensure the pipes are at their most expanded. This pressure is to be maintained until screed application is completed in order to ensure that any leaks are identified immediately and prevent the screed cracking later. 6 bar is a lot higher than a system would normally run.This action can be pressurised for testing purposes with mains water in most cases. REMEMBER: You must be extremely careful to avoid frost unless anti freeze has been added to the water. The flow from the mains tap to the filling point on the flow rail (red) of the manifold and the return/waste hose connected from the drain point of the return manifold (blue) to somewhere the return water can drain to.

Underfloor Heating is a beneficial eco-friendly heating solution that is more efficient and cheaper to run than other forms of heating such as radiators. It can be difficult to understand what is best for you and what the right price to pay should be. This is where we can help. At Underfloor Heating 1 we aim to find the product to best suit your needs that is particular to your property and at a price you won’t find anywhere else. Underfloor Heating 1 promise to beat any like for like quote. We always quote with a full itemised and quantified list of materials after obtaining the information specific to your property – not a generic quote-not all companies do this and beware any supplier that doesn’t! We only source products from the most reputable companies, such as Danfoss, Honeywell and Heatmiser. All of our products are from companies based in the UK or mainland Europe.

When using a heat pump to run underfloor heating we recommend that the underfloor heating pipe is laid at 100mm pipe spacing throughout the property. The main objective of having a heat pump is efficiency and installing the pipes at 100mm spacing maximises the efficiency. Air source heat pump manufacturers’ efficiency data is 7c air temperature and 35C flow temperature. Ground source heat pumps are the same although it is ground temperature and not air temp in the data and this flow temperature is generally only achieved with the pipes at 100mm pipe spacing. The COP (coefficient of performance – how efficient a heat pump is of converting electric into heat) of a heatpump is from these figures and installing the pipes at 200mm spacing would seriously reduce the COP.