Upgrading to a fully pumped system

[dolland]

I have got a Firebird S Oil Boiler which heats my Central Heating and Hot Water. The Hot Water is Gravity Fed; the Central Heating is pumped. Both are activated by the same elderly timer. I want to replace this control system with a fully pumped system with separate control of Hot Water and CE

I have had a couple of plumbers come out to the property over the last few weeks, and they have each given me a quote based on different information, and with quite different prices.

I have been advised to install a Honeywell S Plan System; so far so good. However, the boiler is under a work surface in the kitchen, and the four copper pipes for the flow and returns run up the wall behind the worktop; one plumber has said he needs to take out the worktop and remove some of the cupboard units so that he can get at the boiler to disconnect and seal off one of the ‘circuits’ – he will use a 3-way valve elsewhere in the system. Another plumber has said he doesn’t need access to the boiler itself, he only needs to cut the two pipes where they appear above and behind the work surface (again locating a valve elsewhere) – he doesn’t need to dismantle half the kitchen. Clearly I want to cause as little disruption to my kitchen as possible; there is also a significant price difference because of the work suggested by one plumber over the other.

Is it possible simply to stop using one of the circuits in this manner; wont the boiler overheat or something? If so, as they both seem to suggest, can the pipes simply be cut a couple of feet up from the boiler and so save my kitchen and pocket (the pipes are normally boxed in so will be out of site). The rest of their quoted work appears to be similar.

I hope someone has enough information to advise. Thank you.

 

[DP]

Any alteration that is carried out has to ensure the vent pipe and F+E pipes continue to be uninterupted from boiler to header tank. These pipe will almost certainly be tee'd to the connections at the cylinder coil.

Another point to note is position of pump as this (if aforementioned connections are not altered) could end up leading to pump over into header tank.

A suitable layout of pipe would be a 22mm (vent) pipe teed to boiler flow, 15mm (F+E) pipe within 6" of the vent pipe connected such that convection of heat does not take place, pump and then one or two motorised valves (Y or plan S). For plan S fit a bypass. Top connection at the cylinder should be fitted with a bleed nipple. Keep the elderly timer for HW zone. Fit a programmable roomstat for control of heating. Go one step forward by fitting TRVs in naturaly warm rooms and programmable roomstat in colder room (no TRV fitted here)