Background

            The first call to this address was to investigate a boiler overheat problem.

For some months the overflow had been running intermittently when the boiler was warming up, this had become noticeably worse during the last few days. The water from the overflow was so hot that it had scorched the grass where it landed.  See Pic

The property owner had also noticed steam and condensation in the loft area. 

The boiler – an Ideal W2000 wall hung had been installed for 19 years.

 I tested the thermostat and it worked correctly. I tested the pump which was also working correctly. With any pump or thermostat fault eliminated the symptoms suggested that the heat exchanger was blocked with sludge and residue. 

Talking to the owner further revealed that some of the radiators were intermittent and/or cold at the bottom, hot at the top - a classic sign of residue blockage. 

Remedy

I discussed options with the owner and submitted a quote for boiler replacement, new controls  powerflush, new feed/expansion tank, and TRV’s to all rooms except bathrooms. The quote was accepted.

 The installation took 3 days :-

Day 1  - De-commision Ideal W2000 Boiler and Powerflush the System

Day 2  - Fit TRVs and replace Rad Valves. F/Exp Cistern

Day 3  - Install new boiler and flue and commission.

Method Statement

 A Let-by test and tightness test were satisfactory. The gas supply to the existing boiler was isolated and capped off. The system was drained down and the old boiler disconnected and removed.

Once removed the heat exchanger casing was split open and the excessive build up of debris could clearly be seen inside. See Pic

The system was then powerflushed and the TRVs and Radiator Valves were fitted.

The position of the new boiler was determined by use of the template provided by the manufacturer. The flue was to go through the same opening as the old boiler’s balanced flue and then bricked around. 

The template was used to plot the holes for the boiler mounting plate, which was then fixed to the wall. The new boiler was then hung from the mounting plate. 

The gas supply pipe was modified to feed the new boiler.  

The condensate pipe was then fitted which ran into an existing washing machine waste pipe. 

The flow and return pipes were then connected. 

The flue was then cut to size and fitted. 

The system was then re-filled and vented. 

The gas supply was tightness tested and found satisfactory. 

The boiler electrics were connected, the old boiler’s switched live was used and a new permanent live was taken from the existing double pole switch.  

A new room thermostat and 7-day programmer were fitted. 

The boiler was then fired up and commissioning checks were made. 

The flue pipe penetration was the bricked up and made good.