Really, an internet forum can only generate lots of ideas but with this type of issue you really need to be there to make a reasoned exploration and diagnosis.
We would not make a 'free' visit to quote for this type of work. Frankly, it is a nightmare when two other plumbers have modified a system. We would charge our normal hourly rate for an inspection and only when we had spent a suitable time on site (eg: up to an hour) would we be able to give a likely cost for rectification.
The reason you are getting high quotes is because everyone is covering themselves against unforeseen problems due to the provenance of the system. That is also why some want to repipe everything.
You will also find that many in our trade do not consider a visit 'to quote' is financially worthwhile for a job under £500. You may not agree; but you do not run a heating company and see all the overheads!
We would not make a 'free' visit to quote for this type of work. Frankly, it is a nightmare when two other plumbers have modified a system. We would charge our normal hourly rate for an inspection and only when we had spent a suitable time on site (eg: up to an hour) would we be able to give a likely cost for rectification.
The reason you are getting high quotes is because everyone is covering themselves against unforeseen problems due to the provenance of the system. That is also why some want to repipe everything.
You will also find that many in our trade do not consider a visit 'to quote' is financially worthwhile for a job under £500. You may not agree; but you do not run a heating company and see all the overheads!
