Herbert Hamilton Grundy (1880 - 1932) the only son of John & Louisa Grundy, was born in Hackney London in the autumn of 1880. He was Educated at Islington High School, the Northampton  Institute and Northern Polytechnic.

From 1896 - 1900 during his training he was involved in erecting and supervising H&V work, afterwards working at the Grundy Foundry in Tyldesley near Manchester learning foundry work and pattern making.

From 1910 - 1917 he worked on the design and manufacture of equipment for a system of electrical heating using a method of thermostatic control. During this period he took out several Patents connected with his work.  He developed an electrical method of thermostatic control for equipment such as electric stoves, immersion heaters, and control valves for steam, gas and hot water distribution systems. Herbert patented a thermostatic apparatus for controlling an electric motor driven fan which could be used for heating industrial and educational buildings. He also devised a type of remote reading thermometer.

Upon the death of his father in 1913 he became Managing Director of John Grundy Ltd.

When the Great War started in 1914 John Grundy Ltd was placed under Government control and the firms production was then concentrated upon the maufacture of munitions for the war effort.

He died at the Great Northern Hospital Holloway, Middlesex on the 13th May 1932 at the relatively  young age of 51.

The church of St Peter at Yaxley, just east of the Great North Road near Peterborough, Cambridgeshire has been described as "a large and noble cruciform structure of rubble with stone dressings, and consists of chancel and nave, both with clerestory, aisles, transepts, south porch and an embattled western tower, with pinnacles and octagonal crocketed spire" (Kelly’s Directory 1903).  This is a basic medieval church with the typical architectural layout of side aisles and chapels and built when thermal insulation and warmth in winter simply meant extra layers of clothing should be worn.

The stove and the economiser pipes are covered in the aisle by cast iron floor gratings, and the church is heated by the natural circulation of warmed air up through these gratings.  Although originally some cold fresh air from the outside was fed in through pipes under the aisles, the main air circulation is now achieved using fire proof screens which stand beside the stove and flue pipes, to draw down cool air at the sides of the pit into the base of the stove.  With some of the floor gratings removed the image shows the stove, economiser pipes and the screens on both sides. The stove front and the oil burner are accessed via two cast iron trap doors in the nave floor as shown in the foreground of the photograph below. 

After a number of years in operation for any warm air stove, it becomes necessary to carry out a complete renewal of the brickwork lining to the combustion chamber, due to the deterioration of the refractory brickwork inside the chamber. This is caused by the high temperatures and flame impingement. The high temperatures created within the combustion chamber will also cause the fire cement jointing between the horizontal cast iron sections to harden, eventually crack and become dislodged. These joints will all need to be resealed to prevent the products of combustion escaping from in between the sections out into the air ducts, which supply the warmed air that heats the building.    

The following series of pictures show the combustion chamber of a large size Grundy warm air stove being re-bricked and the joints between each of the sections resealed.